(~s)
1.
A ~ of food is the amount of it that you get in a single serving.
N-COUNT: usu with supp, oft N of n, adj N
2.
You can refer to an amount of something, especially a quality, as a ~ of that thing. (INFORMAL)
It took a generous ~ of entrepreneurial confidence to persevere during this incident.
= amount
N-COUNT: N of n, usu adj N of n