modernize vs build up

modernize and build up both are verbs.

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

modernize (verb)	build up (verb)
make repairs, renovations, revisions or adjustments to	form or accumulate steadily
become technologically advanced	enlarge, develop, or increase by degrees or in stages
	change the use of and make available or usable
	bolster or strengthen
	prepare oneself for a military confrontation