From The Collaborative International Dictionary of English v.0.48 [gcide]:
mannequin \mannequin\ n.
1. a woman who wears clothes to display fashions; a fashion
model. [WordNet sense 1]
Syn: fashion model, model.
[WordNet 1.5]
2. A three-dimensional model of a person, used to display
clothes, especially in retail stores and in window
displays; a dummy. [WordNet sense 2]
Syn: manikin, mannikin, manakin.
[WordNet 1.5]
3. A model of a human form used by tailors to help make
clothing of the proper shape.
[PJC]
From WordNet (r) 3.0 (2006) [wn]:
mannequin
n 1: a woman who wears clothes to display fashions; "she was too
fat to be a mannequin" [syn: mannequin, manikin,
mannikin, manakin, fashion model, model]
2: a life-size dummy used to display clothes [syn: mannequin,
manikin, mannikin, manakin, form]