Adagger,obelisk, orobelus† is atypographical mark that usually indicates afootnote if anasterisk has already been used.^[1] The symbol is also used to indicate death (of people) or extinction (of species or languages).^[2] It is one of the modern descendants of theobelus, a mark used historically by scholars as a critical or highlighting indicator in manuscripts. In older texts, it is called anobelisk.^[3][a]

Adouble dagger, ordiesis,‡ is a variant with twohilts andcrossguards that usually marks a third footnote after the asterisk and dagger.^[5] Thetriple dagger⹋ is a variant with three crossguards and is used bymedievalists to indicate another level of notation.^[6]

The dagger symbol originated from a variant of theobelus, originally depicted by a plain line− or a line with one or two dots÷.^[7] It represented an iron roasting spit, a dart, or the sharp end of ajavelin,^[8] symbolizing the skewering or cutting out of dubious matter.^[9][10][11]

The obelus is believed to have been invented by theHomeric scholarZenodotus as one of a system of editorial symbols. They marked questionable or corrupt words or passages in manuscripts of theHomeric epics.^[4][9] The system was further refined by his studentAristophanes of Byzantium, who first introduced theasterisk and used a symbol resembling a⊤ for an obelus; and finally by Aristophanes' student, in turn,Aristarchus, from whom they earned the name of "Aristarchian symbols".^[12][13]

While the asterisk (asteriscus) was used for corrective additions, the obelus was used for corrective deletions of invalid reconstructions.^[14] It was used when non-attested words are reconstructed for the sake of argument only, implying that the author did not believe such a word or word form had ever existed. Some scholars used the obelus and various other critical symbols, in conjunction with a second symbol known as themetobelos ("end of obelus"),^[15] variously represented as two vertically arranged dots, aγ-like symbol, a mallet-like symbol, or a diagonal slash (with or without one or two dots). They indicated the end of a marked passage.^[16]

It was used much in the same way by later scholars to mark differences between various translations or versions of theBible and other manuscripts.^[17] Theearly ChristianAlexandrian scholarOrigen (c. 184 – c. 253 AD) used it to indicate differences between different versions of theOld Testament in hisHexapla.^[12][15][18]Epiphanius of Salamis (c. 310–320 – 403) used both a horizontal slash or hook (with or without dots) and an upright and slightly slanting dagger to represent an obelus.St. Jerome (c. 347–420) used a simple horizontal slash for an obelus, but only for passages in the Old Testament.^[19] He describes the use of the asterisk and the dagger as: "an asterisk makes a light shine, the obelisk cuts and pierces".^[11]

Isidore of Seville (c. 560–636) described the use of the symbol as follows: "The obelus is appended to words or phrases uselessly repeated, or else where the passage involves a false reading, so that, like the arrow, it lays low the superfluous and makes the errors disappear ... The obelus accompanied by points is used when we do not know whether a passage should be suppressed or not."^[10]

Medieval scribes used the symbols extensively for critical markings of manuscripts. In addition to this, the dagger was also used in notations in earlyChristianity, to indicate a minor intermediate pause in thechanting ofPsalms, equivalent to thequaver rest notation or the trope symbol inHebrew cantillation. It also indicates a breath mark when reciting, along with the asterisk, and is thus frequently seen beside acomma.^[20][21]

In the 16th century, the printer and scholarRobert Estienne (also known as Stephanus inLatin and Stephens in English) used it to mark differences in the words or passages between different printed versions of the GreekNew Testament (Textus Receptus).^[22]

Due to the variations as to the different uses of the different forms of the obelus, there is some controversy as to which symbols can actually be considered an obelus. The⨪ symbol and its variant, the÷, is sometimes considered to be different from other obeli. The term 'obelus' may have referred strictly only to the horizontal slash and the dagger symbols.^{[citation needed]}

The dagger usually indicates afootnote if an asterisk has already been used.^[1] A third footnote employs the double dagger.^[5] Additional footnotes are somewhat inconsistent and represented by a variety of symbols, e.g.,parallels (‖ ),section sign§, and thepilcrow¶ – some of which were nonexistent in early moderntypography. Partly because of this,superscriptnumerals have increasingly been used in modern literature in the place of these symbols, especially when several footnotes are required. Some texts use asterisks and daggers alongside superscripts, using the former for per-page footnotes and the latter forendnotes.

The dagger is also used to indicatedeath,^[5][23]extinction,^[24] orobsolescence.^[1][25] The asterisk and the dagger, when placed beside years, indicate year of birth and year of death respectively.^[5] This usage is particularly common inGerman.^[26] When placed immediately before or after a person's name, the dagger indicates that the person is deceased.^{[5][27][28][29]} In this usage, it is referred to as the "death dagger".^[30] Death-related usages include:

• Inbiology, the dagger next to a taxon name indicates that thetaxon isextinct.^[23][24][31]
• Inchemistry, the double dagger is used in chemical kinetics to indicate a short-livedtransition state species.
• Ingenealogy, the dagger is used traditionally to mark a death in genealogical records.^[32]
• Inchess notation, the dagger may be suffixed to a move to signify the move resulted in a check, and a double dagger denotes checkmate. This is a stylistic variation on the more common+ (plus sign) for a check and# (number sign) for checkmate.
• Inlinguistics, the dagger placed after a language name indicates an extinct language.
• Inphilology, the dagger indicates an obsolete form of a word or phrase.^[1] As language that has become obsolete in everyday use tends to live on elsewhere, the dagger can indicate language only occurring in poetical texts^[33] or "restricted to an archaic, literary style".^[34]
• In theOxford English Dictionary, the dagger symbol indicates an obsolete word.^[25]

Non-death usages include:

• The asteroid37 Fides, the last asteroid to be assigned anastronomical symbol before the practice faded, was assigned the dagger.
• InAnglican chant pointing, the dagger indicates a verse to be sung to the second part of the chant.
• In some early printedBible translations, a dagger or double dagger indicates that a literal translation of a word or phrase is to be found in the margin.
• In librarycataloging, a double dagger delimitsMARC subfields.
• On acricket scorecard or team list, the dagger indicates the team'swicket-keeper.^[35]
• Somelogicians use the dagger as an affirmation ('it is true that ...') operator.^[36]
• Thepalochka is transliterated to a double dagger in theISO 9 standard for convertingCyrillic to Latin
• In psychological statistics the dagger indicates that a difference between two figures is notsignificant to ap<0.05 level, however is still considered a "trend" or worthy of note. Commonly this will be used for a p-value between 0.1 and 0.05.
• Inmathematics and, more often,physics, a dagger denotes theHermitian adjoint of an operator; for example,A^† denotes the adjoint ofA. This notation is sometimes replaced with an asterisk, especially in mathematics. An operator is said to be Hermitian ifA^† =A.^[37]
• Intextual criticism and in some editions of works written before the invention of printing, daggers enclose text that is believed not to be original.^[12]

While daggers are freely used in English-language texts, they are often avoided in other languages because of their similarity to the Christian cross.^{[citation needed]}

• U+2020†DAGGER
• U+2021‡DOUBLE DAGGER
• U+2E36⸶DAGGER WITH LEFT GUARD – used inAlexander John Ellis's "palaeotype" transliteration to indicate retracted pronunciation^[38]
• U+2E37⸷DAGGER WITH RIGHT GUARD – used in Alexander John Ellis's "palaeotype" transliteration to indicate advanced pronunciation^[38]
• U+2E38⸸TURNED DAGGER – used in Alexander John Ellis's "palaeotype" transliteration to indicate retroflex pronunciation^[38]
• U+2E4B⹋TRIPLE DAGGER – A variant with three handles.^[6]

   

Single dagger:

• In HTML:†
• Windows:Alt+0134
• MacOS:⌥ Option+T
• Linux: it appears there is nocompose key sequence, but you can type⇧ Shift+Ctrl+U2020↵ Enter

Double dagger:

• In HTML:‡
• Windows:Alt+0135
• MacOS:⌥ Option+⇧ Shift+7
• Linux:⇧ Shift+Ctrl+U2021↵ Enter

The dagger should not be confused with the symbolsU+271D✝LATIN CROSS,U+253C┼BOX DRAWINGS LIGHT VERTICAL AND HORIZONTAL, orother cross symbols.

The double dagger should not be confused with theU+2628☨CROSS OF LORRAINE, orU+2626☦ORTHODOX CROSS, orU+01C2ǂLATIN LETTER ALVEOLAR CLICK inIPA, orU+167EᙾCANADIAN SYLLABICS WOODS-CREE FINAL TH.

• Annotation – Item of metadata attached to a document
• Marginalia – Marks made in margins of book pages
• Textual criticism – Identification of textual variants