Iambus

n. (Poetry) metrical foot consisting of two syllables (the first syllable is short and the second long or the first syllable is unstressed and the second stressed)

For other senses of the words "iamb" or "iambic", see iamb (disambiguation).An iamb or iambus is a metrical foot used in various types of poetry. Originally the term referred to one of the feet of the quantitative meter of classical Greek prosody: a short syllable followed by a long syllable (as in i-amb). This terminology was adopted in the description of accentual-syllabic verse in English, where it refers to a foot comprising an unstressed syllable followed by a stressed syllable (as in a-bove).
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Noun
1. a metrical unit with unstressed-stressed syllables
(synonym) iamb
(hypernym) metrical foot, foot, metrical unit

(n.)
A foot consisting of a short syllable followed by a long one, as in /mans, or of an unaccented syllable followed by an accented one, as invent; an iambic. See the Couplet under Iambic, n.
  

N M
iambus| metrical foot (one short-one long); iambic trimeter (as invictive)