From WordNet (r) 3.0 (2006) [wn]:
sailboat
n 1: a small sailing vessel; usually with a single mast [syn:
sailboat, sailing boat]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Sailboat \Sail"boat`\, n.
A boat propelled by a sail or sails.
[1913 Webster]