(declines, declining, declined)
Frequency: The word is one of the 1500 most common words in English.
1.
If something declines, it becomes less in quantity, importance, or strength.
The number of staff has declined from 217,000 to 114,000...
Hourly output by workers declined 1.3% in the first quarter...
Union membership and union power are declining fast.
...a declining birth rate.
VERB: V from/to/by amount, V amount, V, V-ing
2.
If you decline something or decline to do something, you politely refuse to accept it or do it. (FORMAL)
He declined their invitation...
The band declined to comment on the story...
He offered the boys some coffee. They declined politely.
VERB: V n, V to-inf, V
3.
If there is a decline in something, it becomes less in quantity, importance, or quality.
There wasn't such a big decline in enrollments after all...
The first signs of economic decline became visible.
N-VAR: oft N with poss, N in n
4.
If something is in decline or on the decline, it is gradually decreasing in importance, quality, or power.
Thankfully the smoking of cigarettes is on the decline...
PHRASE: v-link PHR
5.
If something goes or falls into decline, it begins to gradually decrease in importance, quality, or power.
Libraries are an investment for the future and they should not be allowed to fall into decline.
PHRASE