retain vs hold back

retain and hold back both are verbs.

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

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

retain and hold back: secure and keep for possible future use or application

Other synonyms of retain include hold, keep back.

retain (verb)	hold back (verb)
keep in one's mind	prevent the action or expression of
secure and keep for possible future use or application	hold back, as of a danger or an enemy; check the expansion or influence of
allow to remain in a place or position or maintain a property or feature	hold back; keep from being perceived by others
hold back within	secure and keep for possible future use or application
	wait before acting
	refrain from doing