build vs ramp up

build is a noun but ramp up is not a noun.

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

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

Other synonyms of build include build up, work up.

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

build (verb)	ramp up (verb)
form or accumulate steadily	bolster or strengthen
improve the cleansing action of
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