hold in vs conceal

hold in and conceal both are verbs.

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

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

Other synonyms of hold in include hold back.

hold in (verb)	conceal (verb)
hold back; keep from being perceived by others	hold back; keep from being perceived by others
lessen the intensity of; temper; hold in restraint; hold or keep within limits	prevent from being seen or discovered
close in