prefab vs ready-made

prefab and ready-made both are nouns.

Word	Noun	Adjective	Verb	Adverb
prefab	Yes	Yes	No	No
ready-made	Yes	Yes	No	No

prefab (noun)	ready-made (noun)
a prefabricated structure	a manufactured artifact (as a garment or piece of furniture) that is made in advance and available for purchase

prefab (adjective)	ready-made (adjective)
manufactured in standard sizes to be shipped and assembled elsewhere	made for purchase and immediate use
	commercially produced; not homemade
	repeated regularly without thought or originality