solution (n.)

late 14c., "a solving or being solved," from Old French solucion "division, dissolving; explanation; payment" or directly from Latin solutionem (nominative solutio) "a loosening or unfastening," noun of action from past participle stem of solvere "to loosen, untie, dissolve," from PIE *se-lu-, from reflexive pronoun *s(w)e- (see idiom) + root *leu- "to loosen, divide, cut apart." Meaning "liquid containing a dissolved substance" is first recorded 1590s.