Klein Dictionary, מְנַעֲנֵֽעַ

מְנַעֲנֵֽעַ m.n. 1 a musical instrument (a hapax legomenon in the Bible, occurring Sam. II 6:6 in the pl.); in this sense used only in the pl. NH 2 key (of a piano, typewriter, etc). [Prob. subst. use of the part. of נִעְנַע, Pilp. of נוע (= to wave, move).]