constrain vs tie up

constrain and tie up both are verbs.

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

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

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

Other hyponyms of constrain include bind, tie down, truss, fetter, shackle, enchain, pinion, shackle, impound, pound, pound, pound up, fold, pen up, ground.

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