The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Foot: A rhythmic unit containing two or more syllables in a line of verse. Feet are classified according to a combination of two elements: (1) the number of syllables; and (2) the relative stress or duration of the syllables. In accentual-syllabic verse, the most common metrical form in English, a foot may have any of several combinations of stressed and unstressed syllables but usually consists of one stressed syllable (ˊ) and one or two unstressed syllables (˘). Some theorists also contend that a single stressed syllable may qualify as a foot (the monosyllabic). By contrast, in quantitative verse, a metrical form most often associated with classical Greek and Roman poetry, a foot may consist of any of several combinations of long and short syllables (“long” and “short” referring to the duration of the syllables, i.e., the time needed to pronounce them).
Five types of feet are particularly common in English-language verse: the iamb (˘ˊ), trochee (ˊ˘), anapest (˘˘ˊ), dactyl (ˊ˘˘), and spondee (ˊˊ). Other less common metrical feet are the pyrrhic (˘˘), amphibrach (˘ˊ˘), amphimacer (ˊ˘ˊ), choriambus (ˊ˘˘ˊ), and paeon, which has four forms (ˊ˘˘˘, ˘ˊ˘˘, ˘˘ˊ˘, and ˘˘˘ˊ).
EXAMPLE: Samuel Taylor Coleridge’s poem “Metrical Feet — Lesson for a Boy” (1834) exemplifies seven forms of metrical feet:
Tróchĕe trі́ps frŏm lóng tŏ shórt;
From long to long in solemn sort
Slów Spóndée stálks; stróng fóot! yea ill able.
Évĕr tŏ cóme ŭp wı̇̆th Dácty̆l trı̇̆sýllăblĕ.
Ĭámbics márch frŏm shórt tŏ lóng; —
Wı̇̆th ă leáp ănd ă boúnd thĕ swı̇̆ft Ánăpæ̆sts thróng;
One syllable long, with one short at each side,
Ămphі́br̆achy̆s haśtes wı̇̆th ă státely̆ stride; —
Fі́rst ănd lást béin̆g lóng, mі́ddlĕ shórt, Aḿphı̇̆mácer
Strі́kes hı̇̆s thúndérı̇̆ng hóofs lі́ke ă próud hі́gh-brĕd Rácer… .