Term for size of maximum independent set An independent set is a set of vertices in a graph, no two of which are adjacent.

A maximum independent set is a largest independent set for a given graph G.

Is there a standard term for the size of the largest independent set in a given graph?

If not, what short term can you suggest for this size? Maybe "independence number"?
Yes, it's called the independence number and it's usually denoted $\alpha(G)$.