become vs sober up

become and sober up both are verbs.

Word	Noun	Adjective	Verb	Adverb
become	No	No	Yes	No
sober up	No	No	Yes	No

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

Other hyponyms of become include sober, sober, work, take effect, run, take, break, settle.

become (verb)	sober up (verb)
enter or assume a certain state or condition	become sober after excessive alcohol consumption
come into existence	become more realistic
undergo a change or development
enhance the appearance of