Definition of "Decline" :

noun: a downward slope or bend

noun: a gradual decrease; as of stored charge or current

noun: change toward something smaller or lower

noun: a condition inferior to an earlier condition; a gradual falling off from a better state

verb: grow worse

verb: grow smaller

verb: show unwillingness towards

"He declined to join the group on a hike."

verb: inflect for number, gender, case, etc.

"In many languages, speakers decline nouns, pronouns, and adjectives."

verb: go down in value

verb: go down

"The roof declines here."

verb: refuse to accept