declension in WordNet English dictionary

1. a class of nouns or pronouns or adjectives in Indo-European languages having the same (or very similar) inflectional forms
   "the first declension in Latin"
   declension 
   
2. a downward slope or bend
   descent  declivity  fall  decline  declination  declension  downslope 
   
3. process of changing to an inferior state
   deterioration  decline in quality  declension  worsening 
   
4. the inflection of nouns and pronouns and adjectives in Indo-European languages
   declension