WordNet (r) 3.0 (2006):

bon mot
    n 1: a clever remark [syn: bon mot, mot]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "bon mot":
   aphorism, apothegm, boutade, bright idea, bright thought,
   brilliant idea, conceit, crack, epigram, facetiae, flash of wit,
   flight of wit, gibe, happy thought, mot, nasty crack, persiflage,
   play of wit, pleasantry, quip, quips and cranks, repartee, retort,
   riposte, sally, scintillation, smart crack, smart saying,
   snappy comeback, stroke of wit, turn of thought, wisecrack,
   witticism