The Collaborative International Dictionary of English v.0.48:

Terpsichore \Terp*sich"o*re\, n. [L., fr. Gr. ?; ? enjoyment
   (fr. ? to gladden) + ? dance, dancing.] (Gr. Myth.)
   The Muse who presided over the choral song and the dance,
   especially the latter.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Terpsichore
    n 1: (Greek mythology) the Muse of the dance and of choral song
    2: taking a series of rhythmical steps (and movements) in time
       to music [syn: dancing, dance, terpsichore,
       saltation]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "Terpsichore":
   Apollo, Apollo Musagetes, Calliope, Clio, Erato, Euterpe,
   Melpomene, Orpheus, Pierides, Polyhymnia, Polymnia, Thalia,
   artistic imagination, conception, creative imagination,
   creative power, creative thought, esemplastic imagination,
   esemplastic power, genius, inspiration, muse, mythicization,
   mythification, mythopoeia, poetic imagination, sacred Nine,
   shaping imagination, the Muses, the Nine, tuneful Nine