Iambus
Iambus , noun
[Latin iambus, Greek {not transcribed}; prob. akin to {not transcribed} to throw, assail (the iambus being first used in satiric poetry), and to Latin jacere to throw. Compare Jet a shooting forth.]
(Prosody) A foot consisting of a short syllable followed by a long one, as in amāns, or of an unaccented syllable followed by an accented one, as invent; an iambic. See the Couplet under Iambic, n.