constrain vs impound

constrain and impound both are verbs.

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

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

constrain: to close within bounds, or otherwise limit or deprive of free movement
impound: place or shut up in a pound

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

constrain (verb)	impound (verb)
severely restrict in scope or extent	place or shut up in a pound
to close within bounds, or otherwise limit or deprive of free movement	take temporary possession of as a security, by legal authority
compel to behave in a certain way