(~s)
1.
A ~ is a new type of machine or device which is not yet ready to be made in large numbers and sold.
Chris Retzler has built a ~ of a machine called the wave rotor.
N-COUNT: oft N of n, N n
2.
If you say that someone or something is a ~ of a type of person or thing, you mean that they are the first or most typical one of that type.
He was the ~ of the elder statesman.
N-COUNT: usu N of n