FENTANYL Meaning of FENTANYL in English [ 'fɛntənɪl ]■ noun Medicine a synthetic opiate drug which is a powerful painkiller and tranquillizer.Origin1960s: appar. from fen- (representing phen- ) + -t- + an- + -yl . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004