A spondee (Latin: spondeus) is a metrical foot consisting of two long syllables, as determined by syllable weight in classical meters, or two stressed...

longum, and "u" a brevis. "x x" is known as the Aeolic base, which can be a spondeus "– –", a trochee "– u", or an iamb "u –". The middle foot "– u u –" is...