intransitive verb declined -·clined′, declining -·clin′·ing

1. to bend, turn, or slope downward or aside
2. 1. to sink, as the setting sun
   2. to approach the end; wane the day is declining
3. to lessen in force, health, value, etc.; deteriorate; decay
4. to descend to behavior that is base or immoral
5. to refuse to accept or do something, esp. in a way that is formally polite

Etymology: ME declinen < OFr decliner, to bend, turn aside < L declinare, to bend from, inflect < de-, from (see de-) + clinare, to bend: see lean

transitive verb

1. to cause to bend or slope downward or aside
2. to refuse, esp. in a formally polite way I must decline your offer
3. Gram. to inflect (a noun, pronoun, or adjective) systematically, giving its different forms according to case, number, and gender

noun

1. a declining or becoming less, smaller, etc.; decay
2. a failing of health, etc.
3. a period of decline
4. the last part the decline of life
5. Archaic a wasting disease
6. a downward slope