hold back vs restrain

hold back and restrain both are verbs.

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

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

Other synonyms of hold back include keep, keep back.

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