mid-14c., "to attest (something) with authority," from O.Fr. aprover (Fr. approuver), from L. approbare "to assent to as good, regard as good," from ad- "to" + probare "to try, test something (to find if it is good)," from probus "honest, genuine" (see prove). The meaning extended late 14c. to "show (something) to be good," then to "assent to (something) as good" (early 15c.), especially in ref. to authorities, parliaments, etc.