In poetry, a Metrical Foot that has an unstressed (short) syllable followed by a long (stressed) syllable.
An iamb, when diagrammed, looks somewhat like this: ^ '
Iambic Pentameter is an iambic verse used by Shakespeare, his colleagues and imitators, and by countless romantic poets throughout the ages.
A Poem about Poetry in Iambic Tetrameter
The Iamb! the Trochee! can't you see
they're different kinds of poetry
Oh no, you say, they're types of verse.
So I was cursed until the end
Oh, God! Oh, Friend, can you help me
Release myself from agony?