Probably from Proto-Indo-European *h₁ers- (“tail, butt”) (alternatively reconstructed as Proto-Indo-European *h₃érsos (“backside, buttocks”)), and related to ὄρρος (órrhos, “butt, ass”); see there for more. The connection with οὐραχός (ourakhós, “urachus”), while semantically sound, is phonetically unclear, due to the latter's strange suffix -αχός (-akhós), which has led Beekes to consider a possible Pre-Greek origin for the words (though he still seems to favor Indo-European origin for οὐρά (ourá), at least).[1]
οὐρᾱ́ • (ourā́) f (genitive οὐρᾶς); first declension
| Case / # | Singular | Dual | Plural | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominative | ἡ οὐρᾱ́ hē ourā́ |
τὼ οὐρᾱ́ tṑ ourā́ |
αἱ οὐραί hai ouraí | ||||||||||
| Genitive | τῆς οὐρᾶς tês ourâs |
τοῖν οὐραῖν toîn ouraîn |
τῶν οὐρῶν tôn ourôn | ||||||||||
| Dative | τῇ οὐρᾷ têi ourâi |
τοῖν οὐραῖν toîn ouraîn |
ταῖς οὐραῖς taîs ouraîs | ||||||||||
| Accusative | τὴν οὐρᾱ́ν tḕn ourā́n |
τὼ οὐρᾱ́ tṑ ourā́ |
τᾱ̀ς οὐρᾱ́ς tā̀s ourā́s | ||||||||||
| Vocative | οὐρᾱ́ ourā́ |
οὐρᾱ́ ourā́ |
οὐραί ouraí | ||||||||||
| Notes: |
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