iambus
noun(also iamb)
(specialist)a unit of sound in poetry consisting of one weak or short syllable followed by one strong or long syllable Topics Literature and writingc2(诗歌的)抑扬格 Word Originlate 16th cent.: Latin, from Greek iambos ‘iambus, lampoon’, from iaptein ‘attack verbally’ (because the iambic trimeter was first used by Greek satirists).