restrain vs hold back

restrain and hold back both are verbs.

Word	Noun	Adjective	Verb	Adverb
restrain	No	No	Yes	No
hold back	No	No	Yes	No

As verbs, restrain and hold back are synonyms defined as:

Other synonyms of restrain include keep, keep back.

restrain (verb)	hold back (verb)
prevent the action or expression of	prevent the action or expression of
to close within bounds, or otherwise limit or deprive of free movement	hold back, as of a danger or an enemy; check the expansion or influence of
restrict (someone or something) so as to make free movement difficult	hold back; keep from being perceived by others
prevent (someone or something) from doing something	secure and keep for possible future use or application
	wait before acting
	refrain from doing