From WordNet (r) 3.0 (2006) [wn]:
glissade
n 1: (ballet) a gliding or sliding step in ballet
v 1: perform a glissade, in ballet
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Glissade \Glis`sade"\, n. [F., fr. glisser to slip.]
1. A sliding, as down a snow slope. --Tyndall.
[1913 Webster]
2. A dance step consisting of a glide or slide to one side.
[Webster 1913 Suppl.]