Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

917. Ingratitude — N. ingratitude, thanklessness, oblivion of

benefits, unthankfulness†. benefits forgot; thankless task, thankless office. V. be ungrateful &c adj.; forget benefits; look a gift horse in the mouth. Adj. ungrateful, unmindful, unthankful; thankless, ingrate, wanting in gratitude, insensible of benefits. forgotten; unacknowledged, unthanked†, unrequited, unrewarded; ill- requited. Int. thank you for nothing!, thanks for nothing!, et tu Brute! [Julius Caesar]. Phr. ingratitude! thou marble-hearted fiend [Lear].