become vs sober

become is not an adjective while sober is an adjective.

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

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

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

become (adjective)	sober (adjective)
	not affected by a chemical substance (especially alcohol)
	completely lacking in playfulness
	lacking brightness or color; dull
	dignified and somber in manner or character and committed to keeping promises

become (verb)	sober (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	cause to become sober
enhance the appearance of