Word Origin & History
chaperon1720, from Fr. chaperon "protector," especially "female companion to a young woman," earlier "head covering, hood," from O.Fr. chaperon, dim. of chape "cape." The verb is first attested 1796. "... English writers often erroneously spell it chaperone, app. under the supposition that it requires a fem.
termination." [OED]
"Chaperon ... when used metaphorically means that the experienced married woman shelters the youthful débutante as a hood shelters the face" [1864].