(~d)
1.
When something ~s or when you ~ it, it becomes less in quantity, size, or intensity.
Population growth is decreasing by 1.4% each year...
The number of independent firms ~d from 198 to 96...
Raw-steel production by the nation’s mills ~d 2.1% last week...
Since 1945 air forces have ~d in size...
Gradually ~ the amount of vitamin C you are taking...
We’ve got stable labor, decreasing interest rates, low oil prices.
VERB: V by amount, V from/to amount, V amount, V in n, V n, V-ing
2.
A ~ in the quantity, size, or intensity of something is a reduction in it.
...a ~ in the number of young people out of work...
Bank base rates have fallen from 10 per cent to 6 per cent–a ~ of 40 per cent.
N-COUNT: oft N in/of n