A measurable, patterned unit of poetic rhythm. The concept of the f. has been imported into modern accentual-syllabic prosedy from classical quantitative practice, and disagreement over the nature (and even the "existence") of the f. has been traditional since the late Renaissance. The Eng. f. is customarily defined by the orthodox as a measure of rhythm consisting of 1 accented (stressed, "long") syllable (or 2, as m the spondee) and 1 or more unaccented (unstressed, "short," "slack") syllables. The poetic line in a more or less regular composition, say the traditional prosodists, consists of a number of feet from 1 to 8; conventionally, the feet are to be roughly of the same kind, although metrical variations (q.v.), produced by the occasional "substitution" of different feet, are permissible so long as these substitutions do not efface for long the repeated pattern of the prevailing f.
In traditional Eng. accentual or accentual-syllabic verse the following feet are the most common:
iamb (iambic) x / (as in "destroy") anapest (anapestic) x x / ("intervene") trochee (trochaic) / x ("topsy") dactyl (dactylic) / x x ("merrily") spondee (spondaic) / / ("amen") pyrrhic x x ("the sea | son of | mists")
Iambic and anapestic feet are called ascending or rising feet; trochaic and dactylic, descending or falling. Feet of 2 syllables are called duple feet; feet of 3, triple. Spondaic (except in sprung rhythm, q.v.) and pyrrhic feet are generally "substitute feet. Some prosodists recognize also a monosyllabic f. con- sisting of I stressed syllable. The exemplification of these feet by single words, above, of course distorts their nature: it is important to remember that f. divisions do not necessarily correspond to word divisions, and that the structure of a f. is determined contextually by the nature of the feet which surround it.
The f. bears a close resemblance to the musical bar: both are arbitrary and abstract units of measure which do not necessarily coincide with the phrasal units which they underlie. The major difference between them is that the bar always begins with a "stress."
It is perhaps unfortunate that the terminology of feet is borrowed from classical quantitative prosody, where practice is in general much more regular than in most Eng. verse and where "substitutions" are largely governed by rule rather than by whim or instinct. The Greek and Latin poets included feet such as:
amphibrach x / x bacchius x / / molossus / / / tribrach x x x