ready-made has 1 distinct synonym spread across 1 of its 4 senses. 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 custom-made.
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.
made for purchase and immediate use
a manufactured artifact (as a garment or piece of furniture) that is made in advance and available for purchase
“their apartment was furnished with ready-mades”
1 of the 4 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 ready-made.
Synonyms, antonyms and the broader and narrower relations for ready-made come from Princeton University’s WordNet. Full sources and licences.