(~s)
1.
A ~ of different qualities, ideas, or things is something new that is created by joining them together.
His previous ~s of jazz, pop and African melodies have proved highly successful.
N-COUNT: oft N of pl-n
2.
The ~ of two or more things involves joining them together to form one thing.
His final reform was the ~ of regular and reserve forces.
N-VAR: oft N of pl-n
3.
In physics, ~ is the process in which atomic particles combine and produce a large amount of nuclear energy.
...research into nuclear ~.
N-UNCOUNT