Unknown; in the absence of an explanation, Beekes prefers aPre-Greek borrowing, noting thatMeier-Brügger's derivation from aProto-Indo-European*per-trom(“instrument for getting through”) (from*per-(“to go through, fare”) +*-trom(“instrument suffix”)) is semantically implausible.[1] Not related toHindiपत्थर(patthar,“stone”), which is composed of Indo-European elements.
πέτρᾱ• (pétrā) f (genitiveπέτρᾱς);first declension
| Case / # | Singular | Dual | Plural | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominative | ἡπέτρᾱ hē pétrā | τὼπέτρᾱ tṑ pétrā | αἱπέτραι hai pétrai | ||||||||||
| Genitive | τῆςπέτρᾱς tês pétrās | τοῖνπέτραιν toîn pétrain | τῶνπετρῶν tôn petrôn | ||||||||||
| Dative | τῇπέτρᾳ tēî pétrāi | τοῖνπέτραιν toîn pétrain | ταῖςπέτραις taîs pétrais | ||||||||||
| Accusative | τὴνπέτρᾱν tḕn pétrān | τὼπέτρᾱ tṑ pétrā | τᾱ̀ςπέτρᾱς tā̀s pétrās | ||||||||||
| Vocative | πέτρᾱ pétrā | πέτρᾱ pétrā | πέτραι pétrai | ||||||||||
| Notes: |
| ||||||||||||
FromAncient Greekπέτρα(pétra).
Cognate withMariupol Greekпе́тра(pjétra).
πέτρα• (pétra) f (pluralπέτρες)
| singular | plural | |
|---|---|---|
| nominative | πέτρα(pétra) | πέτρες(pétres) |
| genitive | πέτρας(pétras) | πετρών(petrón) |
| accusative | πέτρα(pétra) | πέτρες(pétres) |
| vocative | πέτρα(pétra) | πέτρες(pétres) |