add up vs outnumber

add up and outnumber both are verbs.

Word	Noun	Adjective	Verb	Adverb
add up	No	No	Yes	No
outnumber	No	No	Yes	No

As verbs, outnumber is a hyponym of add up; that is, outnumber is a word with a more specific, narrower meaning than add up:

Other hyponyms of add up include work out, average, average out, make.

add up (verb)	outnumber (verb)
determine the sum of	be larger in number
be reasonable or logical or comprehensible
to measure up to in kind or quality
add up in number or quantity