Wordnet 3.0
NOUN (1)
1. 
 a menu having individual dishes listed with separate prices; 
ADJECTIVE (1)
1. 
 (of a restaurant meal) having unlimited choices with a separate price for each item; 
ADVERB (1)
1. 
 by ordering items listed individually on a menu; 
- Example: "we ate a la carte"
WordNet (r) 3.0 (2006):
a la carte
    adv 1: by ordering items listed individually on a menu; "we ate
           a la carte"
    adj 1: (of a restaurant meal) having unlimited choices with a
           separate price for each item [ant: prix fixe, table
           d'hote]
    n 1: a menu having individual dishes listed with separate prices