The name of the Muse of dancing in Greek mythology. Arguably the least usable of the nine Muses' names, despite serious competition from Melpomene and Polyhymnia. Those two at least have obvious nicknames, Mel and Polly -- and don't have "sick" in the middle. However, if you use the Greek pronunciation, that syllable is not emphasized, and you've got nicknames Tess, Coco, and Terri.