court of assize vs assizes

court of assize and assizes both are nouns.

Word	Noun	Adjective	Verb	Adverb
court of assize	Yes	No	No	No
assizes	Yes	No	No	No

As nouns, court of assize and assizes are synonyms defined as:

court of assize and assizes: the county courts of England (replaced in 1971 by Crown courts)

Other synonyms of court of assize include court of assize and nisi prius.

court of assize (noun)	assizes (noun)
the county courts of England (replaced in 1971 by Crown courts)	the county courts of England (replaced in 1971 by Crown courts)