c. 1300, "agree, give assent; yield when one has the right, power, or will to oppose," from Old French consentir "agree; comply" (12c.) and directly from Latin consentire "agree, accord," literally "feel together," from assimilated form of com "with, together" (see con-) + sentire "to feel" (see sense (n.)).
"Feeling together," hence, "agreeing, giving permission," a sense evolution that apparently took place in French before the word reached English. Related: Consented; consenting.
c. 1300, "approval, voluntary acceptance of what is done or proposed," also "agreement in sentiment, unity in opinion," from Old French consente, from consentir "agree; comply," from Latin consentire "agree, accord," literally "feel together," from assimilated form of com "with, together" (see con-) + sentire"to feel" (see sense (n.) ).
In Middle English sometimes in a negative sense, "yielding (to sinful desire); connivance." Age of consent, at which one's consent to certain acts is legally valid, is attested from 1650s.
"agreeing, giving consent," c. 1300, present-participle adjective from consent (v.). Consenting adults is attested by 1955, originally in reference to legalizing private homosexuality.
Until modern times used almost exclusively with reference to legal contracts and to the eyes working together reflexively; its sense was extended in the language of sociology and psychology from 1950s (of social groups, non-arranged marriages, etc.) and in the legal discussions of rape and other sex crimes by 1977.
mid-15c., "consent;" 1630s, "condescension," from condescend on model of descent/descend.
1630s, "act of condescending," from French condescendance, from condescendre"to consent, give in, yield," from Latin condescendere "to let oneself down" (see condescend). Related: Condescendency.