commit vs buy into

commit and buy into both are verbs.

Word	Noun	Adjective	Verb	Adverb
commit	No	No	Yes	No
buy into	No	No	Yes	No

As verbs, buy into is a hyponym of commit; that is, buy into is a word with a more specific, narrower meaning than commit:

Other hyponyms of commit include fund, roll over, shelter, tie up, job, speculate.

commit (verb)	buy into (verb)
make a set of changes permanent	buy stocks or shares of a company
transfer to another place so something can be kept or preserved
give entirely to a specific person, activity, or cause
confer a trust upon
cause to be admitted; of persons to an institution
make an investment
perform an act, usually with a negative connotation
engage in or perform