work up vs build

work up is not a noun while build is a noun.

Word	Noun	Adjective	Verb	Adverb
work up	No	No	Yes	No
build	Yes	No	Yes	No

As verbs, work up and build are synonyms defined as:

Other synonyms of work up include build up, progress.

As verbs, work up and build are synonyms defined as:

Other synonyms of work up include build up, ramp up.

work up (noun)	build (noun)
	constitution of the human body
	alternative names for the body of a human being

work up (verb)	build (verb)
develop	form or accumulate steadily
form or accumulate steadily	improve the cleansing action of
come up with	bolster or strengthen
bolster or strengthen	develop and grow
	found or ground
	make by combining materials and parts
	give form to, according to a plan
	build or establish something abstract
	be engaged in building
	order, supervise, or finance the construction of