Figure of speech where words or phrases are used other than their literate sense in order to show an imaginative relationship between diverse things. Figurative language makes poetry more vivid. Such figures of speech include: allegory, apostrophe, hyperbole, irony, litotes, metaphor, metonymy, personification, simile and synecdoche.

The phrase that Robert Williams Buchanan coined for Dante Gabriel Rossetti and his imitators in a scathing review in The Contemporary Review in 1871.

A foot is a basic unit of a meter - a metrical foot normally contains either two or three syllables with varying patterns of stress. See meter.

This form is based on the natural rhythms of phrases and normal pauses, rather than the constraints of metrical feet. Commonly called Vers libre in French, the poetry often involved the counterpoint of stressed and unstressed syllables in unpredictable but clever ways.
American poet Walt Whitman first made extended, successful use of the free verse, and he in turn influenced Baudelaire, who developed the technique in French poetry. In the late 19th and early 20th centuries, we find several poets using some variant of free verse—including Ezra Pound, T. S. Eliot, D. H. Lawrence, William Carlos Williams, and E.E. Cummings.