anapest,  metrical foot consisting of two short or unstressed
syllables followed by one long or stressed syllable. First found
in early Spartan marching songs, anapestic metres were widely
used in Greek and Latin dramatic verse, especially for the
entrance and exit of the chorus. Lines composed primarily of
anapestic feet, often with an additional unstressed syllable at
the end of the first line, are much rarer in English verse.
Because of its jog-trot rhythm, pure anapestic metre was
originally used only in light or popular English verse, but
after the 18th century it appeared in serious poetry. Byron used
it effectively to convey a sense of excitement and galloping in
“The Destruction of Sennacherib”:  In Swinburne’s “By the North
Sea,” however, anapestic trimeter conveys a more subdued effect: