What closes the gap a problem named. A solution is only a solution to the problem as it was stated.
Latin solutio, from solvere (to loosen, to release), from se- (apart) + luere (to loosen); what closes exactly the gap a problem named.
An answer scoped exactly to how a problem was framed — reframe the problem and the same answer can stop counting as a solution at all, without the answer itself having changed.