n. A sloping downward; a declination; a descent; a slope; a declivity.n. A sinking or falling into a lower or inferior state; deterioration; decline.n. Refusal; non-acceptance.n. In grammar: The inflection of nouns, pronouns, and adjectives; strictly, the deviation of other forms of such a word from that of its nominative case; in general, the formation of the various cases from the stem, or from the nominative singular as representing it: thus, in English, man, man's, men, men's; in Latin, rex, regis, regi, regem, rege, in the singular, and reges, regum, regibus, in the plural.n. The rehearsing of a word as declined; the act of declining a word, as a noun.n. A class of nouns declined on the same type: as, first or second declension; the five Latin declensions. Abbreviated decl.