-ин

• -ын (-yn) (after ц)

From Old East Slavic -инъ (-inŭ), from Proto-Slavic *-inъ.

• -ин: IPA^(key): [ʲɪn] (when unstressed)
• -ин: IPA^(key): [ɨn] (when unstressed, after the hushing consonants ш ж ч щ)
• -и́н: IPA^(key): [ˈʲin] (when stressed)

-ин or -и́н • (-in or -ín)

1. 's (possessive suffix)

   ‎Илья́ (Ilʹjá, “Ilya, Elias”) + ‎-и́н (-ín) → ‎Ильи́н (Ilʹín, “Ilya's, Elias's”)

   ‎Лу́ка (Lúka, “Luke”) + ‎-ин (-in) → ‎Лу́кин (Lúkin, “Luke's”)

   Лу́кин день ― Lúkin denʹ ― St. Luke's Day

   ‎Ники́та (Nikíta, “Nikita, Victor”) + ‎-ин (-in) → ‎Ники́тин (Nikítin, “Nikita's, Victor's”)

   ‎Са́ша (Sáša, “Sasha”) + ‎-ин (-in) → ‎Са́шин (Sášin, “Sasha's”)

   ‎дя́дя (djádja, “uncle”) + ‎-ин (-in) → ‎дя́дин (djádin, “uncle's”)

   ‎жена́ (žená, “wife”) + ‎-ин (-in) → ‎же́нин (žénin, “wife's”)

   ‎сестра́ (sestrá, “sister”) + ‎-ин (-in) → ‎се́стрин (séstrin, “sister's”)

• The suffix is usually unstressed even when added to ending-stressed nouns; compare же́нин (žénin) from жена́ (žená). (But not always, cf. Ильи́н (Ilʹín) from Илья́ (Ilʹjá).)

• -ев (-ev), -ов (-ov)