intransitive verb
1. to refuse politely.
He asked her to dance, but she declined.
2. to grow weaker or diminish gradually.
My father’s health is declining and he can no longer live alone.
His fortune has declined in recent years.
3. to slope or incline downward.
The road declines sharply here, so put the truck in low gear.
transitive verb
1. to refuse (to do or to give something).
The mayor declined to be interviewed.
The candidate declined to predict the outcome of the election.
The reporters asked the actress about the incident, but she declined comment.
2. to politely refuse (a thing).
I’m sorry, but I’ll have to decline your offer.
We were busy and had to decline the invitation.
3. in grammar, to list systematically all the inflected forms of (a noun, adjective, or pronoun).
I still remember how to decline the Russian pronouns.
noun
1. a falling off or loss.
I’ve noticed a decline in my strength recently.
Last year, there was a decline in the number of crimes in the city.
2. movement downward.
This chart shows the decline in profits over the last six months.
3. a downward slope.
There is a decline in the road just ahead.