tighten vs constrain

tighten and constrain both are verbs.

Word	Noun	Adjective	Verb	Adverb
tighten	No	No	Yes	No
constrain	No	No	Yes	No

As verbs, tighten and constrain are synonyms defined as:

Other synonyms of tighten include stiffen, tighten up.

tighten (verb)	constrain (verb)
become tight or tighter	severely restrict in scope or extent
make tight or tighter	to close within bounds, or otherwise limit or deprive of free movement
severely restrict in scope or extent	compel to behave in a certain way
narrow or limit