courtyard vs cloister

courtyard and cloister both are nouns.

Word	Noun	Adjective	Verb	Adverb
courtyard	Yes	No	No	No
cloister	Yes	No	Yes	No

As nouns, cloister is a hyponym of courtyard; that is, cloister is a word with a more specific, narrower meaning than courtyard:

Other hyponyms of courtyard include atrium, bailey, food court, forecourt, parvis.

courtyard (noun)	cloister (noun)
an area wholly or partly surrounded by walls or buildings	residence that is a place of religious seclusion (such as a monastery)
	a courtyard with covered walks (as in religious institutions)

courtyard (verb)	cloister (verb)
	seclude from the world in or as if in a cloister
	surround with a cloister
	surround with a cloister, as of a garden