Webster’s Revised Unabridged Dictionary · 1913
Spondee
Spon′dee (spŏn′dē), n. [L. spondeus, Gr. σπονδεῖος (sc. πούς), fr. σπονδή a drink offering, libation, fr. σπένδειν to pour out, make a libation: cf. F. spondée. So called because at libations slow, solemn melodies were used, chiefly in this meter.] (pros.) A poetic foot of two long syllables, as in the Latin word lēgēs.