(~s)
1.
A ~ of something is a tiny amount or proportion of it.
She hesitated for a ~ of a second before responding...
I opened my eyes just a ~.
N-COUNT: oft N of n
2.
A ~ is a number that can be expressed as a proportion of two whole numbers. For example, ? and ? are both ~s.
The students had a grasp of decimals, percentages and ~s.
N-COUNT