/koˈtoj/
OriginePossibly inherited from Late Latin cattus (“cat”), having later been suffixed with -oi (or perhaps directly from a Vulgar Latin cattōneus), the original pronunciation thus being *cătoi. The change from ă to o is not uncommon, occuring in words such as;
porumb < părumb and boteza < *băteza. See also cătușă, which meant cat in archaic language.
Alternatively from a former *cot, from Old Church Slavonic котъ (kotŭ), from Proto-Slavic *kotъ, later being suffixed. Though it's possible the pronunciation is simply a result of Slavicisation.
Formecotoi(plural) · cotoi(accusative, indefinite, nominative, singular) · cotoiul(accusative, definite, nominative, singular) · cotoi(accusative, indefinite, nominative, plural) · cotoii(accusative, definite, nominative, plural) · cotoi(dative, genitive, indefinite, singular) · cotoiului(dative, definite, genitive, singular) · cotoi(dative, genitive, indefinite, plural) · cotoilor(dative, definite, genitive, plural) · cotoiule(singular, vocative) · cotoilor(plural, vocative) · lui Cotoi(dative, genitive)