tie up vs constrain

tie up and constrain both are verbs.

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

As verbs, constrain is a hypernym of tie up; that is, constrain is a word with a broader meaning than tie up:

tie up: secure with or as if with ropes
constrain: to close within bounds, or otherwise limit or deprive of free movement

Other hypernyms of tie up include confine, hold, restrain.

tie up (verb)	constrain (verb)
secure with or as if with ropes	severely restrict in scope or extent
finish the last row	to close within bounds, or otherwise limit or deprive of free movement
restrain from moving or operating normally	compel to behave in a certain way
secure in or as if in a berth or dock
invest so as to make unavailable for other purposes