The act or the state of declining; declination; descent; slope.
- Linguistics In certain languages, the inflection of nouns, pronouns, and adjectives in categories such as case, number, and gender.
- Linguistics A class of words of one language with the same or a similar system of inflections, such as the first declension in Latin.
- A descending slope; a descent.
- A decline or decrease; deterioration: "States and empires have their periods of declension” ( Laurence Sterne).
- A deviation, as from a standard or practice.