Etymology (/ˌɛtɪˈmɒlədʒi/ET-im-OL-ə-jee^[1]) is the study of the origin and evolution of words—including their constituent units ofsound andmeaning—across time.^[2] In the 21st century a subfield withinlinguistics, etymology has become a more rigorously scientific study.^[1] Most directly tied tohistorical linguistics,philology, andsemiotics, it additionally draws upon comparativesemantics,morphology,pragmatics, andphonetics in order to attempt a comprehensive and chronological catalogue of all meanings and changes that a word (and its related parts) carries throughout its history. The origin of any particular word is also known as itsetymology.

For languages with a longwritten history, etymologists make use of texts, particularly texts about the language itself, to gather knowledge about how words were used during earlier periods, how they developed in meaning andform, or when and how they entered the language. Etymologists also apply the methods ofcomparative linguistics to reconstruct information about forms that are too old for any direct information to be available. By analyzing related languages with a technique known as thecomparative method, linguists can make inferences about their shared parent language and its vocabulary. In this way,word roots in many European languages, for example, can be traced back to the origin of theIndo-European language family.

Even though etymological research originated from the philological tradition, much current etymological research is done on language families where little or no early documentation is available, such asUralic andAustronesian.

The wordetymology is derived from the Ancient Greek wordἐτυμολογία (etumologíā), itself fromἔτυμον (étumon), meaning'true sense or sense of a truth', and the suffix-logia, denoting'the study or logic of'.^[3][4]

Theetymon refers to the predicate (i.e. stem^[5] or root^[6]) from which a later word or morpheme derives. For example, the Latin wordcandidus, which means'white', is the etymon of Englishcandid. Relationships are often less transparent, however. Englishplace names such asWinchester,Gloucester,Tadcaster share different forms of asuffix that originated as the Latincastrum'fort'.

Reflex is the name given to a descendant word in a daughter language, descended from an earlier language. For example, Modern English heat is the reflex of the Old Englishhǣtu. Rarely, this word is used in reverse, and the reflex is actually the root word rather than the descendant word. However, this usage is usually filled by the termetymon instead. A reflex will sometimes be described simply as adescendant,derivative orderived from an etymon (but see below).^{[citation needed]}

Cognates orlexical cognates are sets of words that have been inherited in direct descent from an etymological ancestor in a common parent language.^[7]Doublets oretymological twins ortwinlings (or possibly triplets, and so forth) are specifically cognates within the same language. Although they have the same etymological root, they tend to have different phonological forms, and to have entered the language through different routes.

Aroot is the source of related words within a single language (no language barrier is crossed).Similar to the distinction betweenetymon androot, a nuanced distinction can sometimes be made between adescendant and aderivative.

Aderivative is one of the words which have their source in a root word, and were at some time created from the root word using morphological constructs such as suffixes, prefixes, and slight changes to the vowels or to the consonants of the root word. For example:unhappy,happily, andunhappily are all derivatives of the root wordhappy. The termsroot andderivative are used in the analysis ofmorphological derivation within a language in studies that are not concerned with historical linguistics and that do not cross the language barrier.

Etymologists apply a number of methods to study the origins of words, some of which are:

• Philological research. Changes in the form and meaning of the word can be traced with the aid of older texts, if such are available.
• Making use ofdialectological data. The form or meaning of the word might show variations betweendialects, which may yield clues about its earlier history.
• Thecomparative method. By a systematic comparison of related languages, etymologists may often be able to detect which words derive from their common ancestor language and which were instead later borrowed from another language.
• The study ofsemantic change. Etymologists must often make hypotheses about changes in the meaning of particular words. Such hypotheses are tested against the general knowledge of semantic shifts. For example, the assumption of a particular change of meaning may be substantiated by showing that the same type of change has occurred in other languages as well.

Etymological theory recognizes that words originate through a limited number of basic mechanisms, the most important of which arelanguage change, borrowing (i.e., the adoption ofloanwords from other languages);word formation such asderivation andcompounding; andonomatopoeia andsound symbolism (i.e., the creation of imitative words such asclick orgrunt).

While the origin of newly emerged words is often more or less transparent, it tends to become obscured through time due to sound change or semantic change. Due tosound change, it is not readily obvious that the English wordset is related to the wordsit (the former is originally acausative formation of the latter). It is even less obvious thatbless is related toblood (the former was originally a derivative term meaning 'to mark with blood').

Semantic change may also occur. For example, the English wordbead originally meant 'prayer', and acquired its modern meaning through the practice of counting the recitation of prayers by using small objects strung together (beads). One type of semantic change involves the quotidianisation ofmetaphor.^[8]Thus the word "trauma", the predecessors of which apparently referenced an "open hole" in the body, has passed through some metaphorical stage or stages and now often refers to some sort of psychological wound.^[9]

The search for meaningful origins for familiar or strange words is far older than the modern understanding of linguistic evolution and the relationships of languages, which began no earlier than the 18th century. Etymology has been a form of witty wordplay, in which the supposed origins of words were creatively imagined to satisfy contemporary requirements. For example, the Greek poetPindar (bornc. 522 BCE) employed inventive etymologies to flatter his patrons.Plutarch employed etymologies insecurely based on fancied resemblances in sounds.Isidore of Seville'sEtymologiae was an encyclopedic tracing of "first things" that remained uncritically in use in Europe until the sixteenth century.Etymologicum Genuinum is a grammatical encyclopedia edited atConstantinople during the 9th century, one of several similarByzantine works. The 13th-centuryGolden Legend, as written byJacobus de Voragine, begins eachhagiography of a saint with a fancifulexcursus in the form of an etymology.^[10]

Inancient India,Sanskrit linguists and grammarians were the first to undertake comprehensive analyses of linguistics and etymology. The study of Sanskrit etymology has provided Western scholars with the basis ofhistorical linguistics and modern etymology. Four of the most famous Sanskrit linguists are:

• Yāska (c. 6th–5th centuries BCE)
• Pāṇini (c. 520—460 BCE)
• Kātyāyana (6th-4th centuries BCE)
• Patanjali (2nd century BCE)

These were not the earliest Sanskrit grammarians, but rather followed an earlier line of scholars who lived several centuries earlier, who includedŚākaṭāyana (814–760 BCE), and of whom very little is known. The earliest of attested etymologies can be found in theVedas, in the philosophical explanations of theBrahmanas,Aranyakas, andUpanishads.

The analyses ofSanskrit grammar done by the previously mentioned linguists involved extensive studies on the etymology (calledNirukta orVyutpatti in Sanskrit) of Sanskrit words, because the ancient Indians considered sound and speech itself to be sacred and, for them, the words of the Vedas contained deep encoding of the mysteries of the soul and God.

One of the earliest philosophical texts of the Classical Greek period to address etymology was theSocratic dialogueCratylus (c. 360 BCE) byPlato. During much of the dialogue,Socrates makes guesses as to the origins of many words, including the names of the gods. In hisodes, Pindar spins complimentary etymologies to flatter his patrons.Plutarch (Life ofNuma Pompilius) spins an etymology forpontifex, while explicitly dismissing the obvious, and actual "bridge-builder":

The priests, called Pontifices.... have the name of Pontifices frompotens, powerful because they attend the service of the gods, who have power and command overall. Others make the word refer to exceptions of impossible cases; the priests were to perform all the duties possible; if anything lays beyond their power, the exception was not to be cavilled. The most common opinion is the most absurd, which derives this word from pons, and assigns the priests the title of bridge-makers. The sacrifices performed on the bridge were amongst the most sacred and ancient, and the keeping and repairing of the bridge attached, like any other public sacred office, to the priesthood.

Isidore of Seville compiled a volume of etymologies to illuminate the triumph of religion. Each saint's legend inJacobus de Voragine'sGolden Legend begins with an etymological discourse on their name:

Lucy is said of light, and light is beauty in beholding, after that S. Ambrose saith: The nature of light is such, she is gracious in beholding, she spreadeth over all without lying down, she passeth in going right without crooking by right long line; and it is without dilation of tarrying, and therefore it is showed the blessed Lucy hath beauty of virginity without any corruption; essence of charity without disordinate love; rightful going and devotion to God, without squaring out of the way; right long line by continual work without negligence of slothful tarrying. In Lucy is said, the way of light.^[11]

Etymology in the modern sense emerged in the late 18th-century European academia, in the context of theAge of Enlightenment, although preceded by 17th-century pioneers such asMarcus Zuerius van Boxhorn,Gerardus Vossius,Stephen Skinner,Elisha Coles, andWilliam Wotton. The first known systematic attempt to prove the relationship between two languages on the basis of similarity ofgrammar andlexicon was made in 1770 by the Hungarian,János Sajnovics, when he attempted to demonstrate the relationship betweenSami andHungarian.^[12]

The origin of modernhistorical linguistics is often traced toWilliam Jones, a Welsh philologist living in India, who in 1782 observed the genetic relationship between Greek and Latin. Jones published hisThe Sanscrit Language in 1786, laying the foundation for the field ofIndo-European studies. However, as early as 1727, a Jesuit missionary in India, père Gargam, theorized that Sanskrit could be a "mother tongue arrived from another country" forTelugu andKannada because they contained many of the same Sanskrit terms; and in a letter to Abbé Barthélemy of theAcadémie des Inscriptions et Belles Lettres in 1767, another Jesuit missionary in India, pèreGaston-Laurent Coeurdoux, posed the question of the origin of the Sanskrit language and systematically argued his hypothesis of a "commune origine" of Sanskrit, Latin, and Greek, even putting Sanskrit terms and their Latin equivalents in columns.^[13] Although they sent many Sanskrit-related texts to theBibliothèque du roi, such as literary translations, grammars, dictionaries, and other works, theJesuit Missionaries in theCarnatic Region between 1695-1762, includingJean Calmette, Coeurdoux, Gargam,Jean François Pons, and others, have only recently begun receiving more attention in modern scholarship for their early contributions to fields like Indo-European Studies, historical linguistics, and comparative philology.^[13][14]

The study of etymology inGermanic philology was introduced byRasmus Rask in the early 19th century and elevated to a high standard with theDeutsches Wörterbuch (German Dictionary) compiled by theBrothers Grimm. The successes of the comparative approach culminated in theNeogrammarian school of the late 19th century. Still,Friedrich Nietzsche used etymological strategies (principally and most famously inOn the Genealogy of Morality, but also elsewhere) to argue that moral values have definite historical origins, where the meaning of concepts such as good and evil are shown to have changed over time according to the value-system that appropriates them. This strategy gained popularity in the 20th century, and philosophers, such asJacques Derrida, have used etymologies to indicate former meanings of words to de-center the "violent hierarchies" of Western philosophy.

• Ernest Klein (1899–1983), Hungarian-born Romanian-Canadian linguist, etymologist
• Marko Snoj (born 1959), Indo-Europeanist, Slavist, Albanologist, lexicographer, and etymologist
• Anatoly Liberman (born 1937), linguist, medievalist, etymologist, poet, translator of poetry and literary critic
• Michael Quinion (bornc. 1943)

• Etymological dictionary
• Lists of etymologies
• Bongo-Bongo – Name for an imaginary language in linguistics
• Etymological fallacy – Fallacy in which a word's history defines its meaning
• False cognate – Words that look or sound alike, but are not related
• False etymology – Popular, but false belief about word origins
• Folk etymology – Process of reinterpretive word formation
• Malapropism – Misuse of a word
• Pseudoscientific language comparison – Form of pseudo-scholarship
• Onomastics – Study of proper names
• Wörter und Sachen – science school of linguisticsPages displaying wikidata descriptions as a fallback
• Suppletion – A word having inflected forms from multiple unrelated stems

• Alfred Bammesberger.English Etymology. Heidelberg: Carl Winter, 1984.
• Philip Durkin. "Etymology", inEncyclopedia of Language and Linguistics, 2nd edn. Ed. Keith Brown. Vol. 4. Oxford: Elsevier, 2006, pp. 260–267.
• Philip Durkin.The Oxford Guide to Etymology. Oxford University Press, 2009.
• William B. Lockwood.An Informal Introduction to English Etymology. Montreux, London: Minerva, 1995.
• Yakov Malkiel.Etymology. Cambridge University Press, 1993.
• Alan S. C. Ross.Etymology, with a special reference to English. Fair Lawn, NJ: Essential Books; London: Deutsch, 1958.
• Michael Samuels.Linguistic Evolution: With Special Reference to English. Cambridge University Press, 1972.
• Bo Svensén. "Etymology", chap. 19 ofA Handbook of Lexicography: The Theory and Practice of Dictionary-Making. Cambridge University Press, 2009.
• Walther von Wartburg.Problems and Methods in Linguistics, rev. edn. with the collaboration of Stephen Ullmann. Trans. Joyce M. H. Reid. Oxford: Blackwell, 1969.

• List of etymologies of words in 90+ languages
• Online Etymology Dictionary