From WordNet (r) 3.0 (2006) [wn]:
limo
n 1: large luxurious car; usually driven by a chauffeur [syn:
limousine, limo]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
limo \limo\ n.
Limousine; -- a shortened form.
Syn: limousine.
[WordNet 1.5]