n.
1.change toward something smaller or lower
2.a condition inferior to an earlier condition
3.a gradual decrease
4.a downward slope or bend decline v.
1.grow worse
2.refuse to accept
3.show unwillingness towards
4.grow smaller
5.go down
6.go down in value
7.inflect for number, gender, case, etc., "in many languages, speakers decline nouns, pronouns, and adjectives"