to confirm by expressing consent, approval, or formal sanction: to ratify a constitutional amendment.
2.
to confirm (something done or arranged by an agent or by representatives) by such action.
Origin: 1325–75; Middle English ratifien < Middle French ratifier < Medieval Latin ratificāre, equivalent to Latin rat(us) calculated (see rate1) + -ificāre-ify
c.1357, from O.Fr. ratifier (1294), from M.L. ratificare "confirm, approve," lit. "fix by reckoning," from L. ratus "fixed, valid" (pp. of reri "to reckon, think") + root of facere "to make" (see factitious).