Polyhymnia | Webster's Dictionary of the English Language

Polyhymnia
Pŏlyhymnĭa (Pŏlymnĭa, Poët. ap. Anth. Lat. 1, p. 51 Burm.), ae, f., = Πολυμνία (she of many hymns)...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
Polyhymnia
Polyhymnia ae, f , Πολύμνια(rich in song), one of the Muses, H., O. ...

An Elementary Latin Dictionary