From The Collaborative International Dictionary of English v.0.48 :
Liqueur \Li`queur"\ (l[-e]`k[~e]r"), n. [F. See Liquor.]
An aromatic alcoholic cordial.
[1913 Webster]
Note: Some liqueurs are prepared by infusing certain woods,
fruits, or flowers, in either water or alcohol, and
adding sugar, etc. Others are distilled from aromatic
or flavoring agents.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
liqueur
n 1: strong highly flavored sweet liquor usually drunk after a
meal [syn: liqueur, cordial]