keep to oneself vs keep back

keep to oneself and keep back both are verbs.

Word	Noun	Adjective	Verb	Adverb
keep to oneself	No	No	Yes	No
keep back	No	No	Yes	No

As verbs, keep back is a hypernym of keep to oneself; that is, keep back is a word with a broader meaning than keep to oneself:

Other hypernyms of keep to oneself include withhold.

keep to oneself (verb)	keep back (verb)
withhold information	prevent the action or expression of
shun the company of others	hold back; refuse to hand over or share
	secure and keep for possible future use or application