revenge (n.) Look up revenge at Dictionary.com
1540s, from Middle French revenge, back-formation from revengier (see revenge (v.)).
revenge (v.) Look up revenge at Dictionary.com
late 14c., from Old French revengier, variant of revenchier "take revenge, avenge" (13c., Modern French revancher), from re-, intensive prefix (see re-), + vengier "take revenge," from Latin vindicare "to lay claim to, avenge, punish" (see vindication).
To avenge is "to get revenge" or "to take vengeance"; it suggests the administration of just punishment for a criminal or immoral act. Revenge seems to stress the idea of retaliation a bit more strongly and implies real hatred as its motivation. ["The Columbia Guide to Standard American English," 1993]