Weakly compact can refer to:
Weakly compact cardinal, an infinite cardinal number on which every binary relation has an equally large homogeneous subset Weakly compact set, a compact set in a space with the weak topology Weakly compact set, a set that has some but not all of the properties of compact sets, for example: Sequentially compact space, a set in which every infinite sequence has a convergent subsequence Limit point compact, a set in which every infinite subset of X has a limit point