a la carte has no recorded synonym. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is table d'hote.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a menu having individual dishes listed with separate prices
(of a restaurant meal) having unlimited choices with a separate price for each item
1 of the 3 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for a la carte.
Synonyms, antonyms and the broader and narrower relations for a la carte come from Princeton University’s WordNet. Full sources and licences.