(OALD 5)(in poetry) of or using a rhythm each part of which (an IAMBUS) consists of one short or weak syllable followed by one long or strong syllable.
the meter of the spoken parts in tragedy and old comedy; an iamb consists of two syllables, a short syllable followed by a long syllable.
of or consisting of iambs; "iambic pentameter"
an unstressed/stressed combination of syllables in a metrical foot
A metrical foot consisting of one short syllable followed by one long syllable, or of one unstressed syllable followed by one stressed syllable.