early 14c., "consent, approval," from Old French assent, a back-formation from assentir "to agree" (see assent (v.)). "Assent is primarily an act of the understanding; consent is distinctly the act of the will: as, I assent to that proposition; I consent to his going" [Century Dictionary].
1788, mystical word or combination of letters in Hindu religions and Buddhism; originally an utterance of assent.
1630s, "rest, quiet, satisfaction," from French acquiescence, noun of action from acquiescer "to yield or agree to; be at rest" (see acquiesce). Meaning "silent consent, passive assent" is recorded from 1640s.
"express a liking or satisfaction," late 15c., from Latin approbatus, past participle of approbare "to assent to (as good), favor" (see approbation). Related: Approbated; approbating.
"divine spirit, presiding divinity," 1620s, from Latin numen "divine will, divinity," literally "a nod" (the notion is "divine approval expressed by nodding the head"), from nuere "to nod" (assent); see numinous.
c. 1300, apreven, approven, "to demonstrate, prove," from Old French aprover (Modern French approuver) "approve, agree to," from Latin approbare "to assent to as good, regard as good," from ad "to" (see ad-) + probare "to try, test something (to find if it is good)," from probus "honest, genuine" (see prove).
The meaning was extended by late 14c. to "regard or assent to (something) as good or superior; commend; sanction, endorse, confirm formally," especially in reference to the actions of authorities, parliaments, etc. Related: Approved; approving.