"characterized by illicit desire, lustful," mid-15c., from Latin concupiscentem (nominative concupiscens), present participle of concupiscere "to long for, covet" (see concupiscence).
"ardent desire, improper or illicit desire, lustful feeling," mid-14c., from Old French concupiscence and directly from Late Latin concupiscentia "eager desire," from present-participle stem of Latin concupiscere, inceptive of concupere "to be very desirous of," from assimilated form of com-, here perhaps an intensive prefix (see com-), + cupere "to long for" (see cupidity). Used in Vulgate to translate Greek epithymia.
"1.5-ounce shot glass," 1836, American English, in early use also of the drink itself, probably from jigger "illicit distillery" (1824), a word of unknown origin. Or else perhaps from jigger (n.2) "tiny mite or flea." As a name for various appliances the word is attested by 1726, from jig. In telegraphy it was a small transformer used for regulating and maintaining the difference of potential between terminals.
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]