The Collaborative International Dictionary of English v.0.48:
Erato \Er"a*to\, n. [L., fr. Gr. ?, fr. ? to love.] (Class. Myth.) The Muse who presided over lyric and amatory poetry. [1913 Webster]WordNet (r) 3.0 (2006):
Erato n 1: (Greek mythology) the Muse of lyric and love poetry