1. The systematic variation of word forms showing grammatical case, number, and gender in many languages
   "The declension of the Latin noun 'puella' (girl) includes forms like 'puella', 'puellae', 'puellam'"
    
2. A class of nouns, pronouns or adjectives in Indo-European languages having the same (or very similar) inflectional forms
   "the first declension in Latin"
    
3. Process of changing to an inferior state
   "The declension of the neighbourhood was evident in its abandoned buildings";
   - deterioration, decline in quality, worsening
    
4. A downward slope or bend
   "The path followed the natural declension of the hillside";
   - descent, declivity, fall, decline, declination, downslope

Derived forms: declensions

Type of: category, class, decline, diminution, family, incline, inflection, inflexion [Brit], side, slope

Encyclopedia: Declension