The Collaborative International Dictionary
Properispomenon
Properispomenon \Pro*per`i*spom"e*non\, n.; pl. Properispomena. [NL., fr. Gr. ?, fr. ? to circumflex on the penult; ? before + ? to circumflex. See Perispomenon.] (Gr. Gram.) A word which has the circumflex accent on the penult.
Wiktionary
properispomenon
a. In Greek grammar, having a circumflex accent on the penultimate syllable. n. A word having such an accent.