Answer: declension

AnswerCrossword Clue
declensiona system of cases and case-endings
declensionA condition of decline or moral deterioration
declensionThe class to which a noun or adjective is assigned according to the manner of this variation
declension(in the grammar of Latin, Greek, and other languages) The variation of the form of a noun, pronoun, or adjective, by which its grammatical case, number, and gender are identified