constrain vs pound

constrain is not a noun while pound is a noun.

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

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

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

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

constrain (noun)	pound (noun)
	the act of pounding (delivering repeated heavy blows)
	a public enclosure for stray or unlicensed dogs
	a symbol for a unit of currency (especially for the pound sterling in Great Britain)
	a nontechnical unit of force equal to the mass of 1 pound with an acceleration of free fall equal to 32 feet/sec/sec
	the basic unit of money in Great Britain and Northern Ireland; equal to 100 pence
	the basic unit of money in Cyprus; equal to 100 cents
	the basic unit of money in Egypt; equal to 100 piasters
	formerly the basic unit of money in Ireland; equal to 100 pence
	the basic unit of money in Lebanon; equal to 100 piasters
	the basic unit of money in the Sudan; equal to 100 piasters
	the basic unit of money in Syria; equal to 100 piasters
	16 ounces avoirdupois
	a unit of apothecary weight equal to 12 ounces troy

constrain (verb)	pound (verb)
severely restrict in scope or extent	break down and crush by beating, as with a pestle
to close within bounds, or otherwise limit or deprive of free movement	hit hard with the hand, fist, or some heavy instrument
compel to behave in a certain way	strike or drive against with a heavy impact
	place or shut up in a pound
	shut up or confine in any enclosure or within any bounds or limits
	partition off into compartments
	move rhythmically
	move heavily or clumsily