a factor or set of factors which suffices to make an event occur, which forces an event or result to occur

where p and q are statements, p is a sufficient condition for q if p's truth guarantees the truth of q; it is impossible for p to be true and q to be false; if p is a sufficient condition for q, then the conditional "if p, then q" is true.

A condition that is enough (suffices) for something else to follow. Being born in the United States is a sufficient condition for citizenship (thought you may also acquire citizenship through other means). Sufficient conditions become the antecedents of conditionals.