hold in vs hold back

hold in and hold back both are verbs.

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

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

Other synonyms of hold in include conceal.

As verbs, hold back is a hypernym of hold in; that is, hold back is a word with a broader meaning than hold in:

hold in: lessen the intensity of; temper; hold in restraint; hold or keep within limits
hold back: prevent the action or expression of

Other hypernyms of hold in include keep, keep back, restrain.

hold in (verb)	hold back (verb)
hold back; keep from being perceived by others	prevent the action or expression of
lessen the intensity of; temper; hold in restraint; hold or keep within limits	hold back, as of a danger or an enemy; check the expansion or influence of
close in	hold back; keep from being perceived by others
	secure and keep for possible future use or application
	wait before acting
	refrain from doing