-ոյ

From Proto-Indo-European *-es, *-os and partly perhaps from the genitive singular case ending -ոյ (-oy) (see Etymology 2).

-ոյ • (-oy)

1. found in few words

• J̌ahukyan, Geworg (1998), “-ոյ”, in Hin hayereni verǰacancʿneri cagumə [The Origin of Old Armenian Suffixes] (Hayocʿ lezvi hamematakan kʿerakanutʿyan harcʿer; 2) (in Armenian), Yerevan: Anania Širakacʿi, pages 5–48

From the Proto-Indo-European thematic singular genitive ending *-osyo, taken over from the pronominal declension. Cognate with Sanskrit -अस्य (-asya), Old Persian [script needed] (-ahyā), Homeric Ancient Greek -οιο (-oio), Old Latin -osio, Faliscan -osio and Lepontic [script needed] (-oiso).

-ոյ • (-oy)

1. the genitive singular case ending of o-stem nouns

   գետոյ ― getoy ― genitive singular of գետ (get)

2. the dative singular case ending of o-stem nouns

   գետոյ ― getoy ― dative singular of գետ (get)

3. the ablative singular case ending of o-stem nouns

   գետոյ ― getoy ― dative singular of գետ (get)

• Martirosyan, Hrach (2013), “The place of Armenian in the Indo-European language family: the relationship with Greek and Indo-Iranian”, in Journal of Language Relationship‎, issue 10, § 3.2, page 90
• Matasović, Ranko (2009) A Grammatical Sketch of Classical Armenian‎ (pdf), Zagreb, page 18
• Godel, Robert (1975) An introduction to the study of classical Armenian, Wiesbaden: Dr. Ludwig Reichert Verlag, page 104