Leotard

[lee-uh-tahrd] /ˈli əˌtɑrd/

noun
1.
a skintight, one-piece garment for the torso, having a high or low neck, long or short sleeves, and a lower portion resembling either briefs or tights, worn by acrobats, dancers, etc.
/ˈlɪəˌtɑːd/
noun
1.
a tight-fitting garment covering the body from the shoulders down to the thighs and worn by acrobats, ballet dancers, etc
2.
(pl) (US & Canadian) another name for tights (sense 1b)
n.

1881, leotards, named for Jules Léotard (1830-1870), popular French trapeze artist, who performed in such a garment.