commit vs tie up

commit and tie up both are verbs.

Word	Noun	Adjective	Verb	Adverb
commit	No	No	Yes	No
tie up	No	No	Yes	No

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

Other hyponyms of commit include fund, roll over, shelter, job, speculate, buy into.

commit (verb)	tie up (verb)
make a set of changes permanent	secure with or as if with ropes
transfer to another place so something can be kept or preserved	finish the last row
give entirely to a specific person, activity, or cause	restrain from moving or operating normally
confer a trust upon	secure in or as if in a berth or dock
cause to be admitted; of persons to an institution	invest so as to make unavailable for other purposes
make an investment
perform an act, usually with a negative connotation
engage in or perform