restrain vs keep

restrain is not a noun while keep is a noun.

Word	Noun	Adjective	Verb	Adverb
restrain	No	No	Yes	No
keep	Yes	No	Yes	No

As verbs, restrain and keep are synonyms defined as:

Other synonyms of restrain include hold back, keep back.

As verbs, keep is a hypernym of restrain; that is, keep is a word with a broader meaning than restrain:

restrain: prevent (someone or something) from doing something
keep: stop (someone or something) from doing something or being in a certain state

Other hypernyms of restrain include prevent.

restrain (noun)	keep (noun)
	the main tower within the walls of a medieval castle or fortress
	a cell in a jail or prison
	the financial means whereby one lives

restrain (verb)	keep (verb)
prevent the action or expression of	prevent (food) from rotting
to close within bounds, or otherwise limit or deprive of free movement	prevent the action or expression of
restrict (someone or something) so as to make free movement difficult	stick to correctly or closely
prevent (someone or something) from doing something	maintain by writing regular records
	supply with necessities and support
	hold and prevent from leaving
	retain possession of
	look after; be the keeper of; have charge of
	retain rights to
	maintain for use and service
	have as a supply
	store or keep customarily
	stop (someone or something) from doing something or being in a certain state
	allow to remain in a place or position or maintain a property or feature
	conform one's action or practice to
	behave as expected during of holidays or rites
	cause to continue in a certain state, position, or activity
	supply with room and board
	maintain in safety from injury, harm, or danger
	fail to spoil or rot
	continue a certain state, condition, or activity
	to rear