c. 1300, "love," from Old French amor "love, affection, friendship; loved one" (11c.), from Latin amor "love, affection, strong friendly feeling" (of feelings for sons or brothers, but it especially meant sexual love), from amare "to love" (see Amy). The accent shifted 15c.-17c. to the first syllable as the word became nativized, then shifted back as the sense "illicit love affair" became primary 17c. and the word was felt to be a euphemism.
A common ME word for love, later accented ámour (cf. enamour). Now with suggestion of intrigue and treated as a F[rench] word. [Weekley]