come across vs regain

come across and regain both are verbs.

Word	Noun	Adjective	Verb	Adverb
come across	No	No	Yes	No
regain	No	No	Yes	No

As verbs, regain is a hypernym of come across; that is, regain is a word with a broader meaning than come across:

come across: find unexpectedly
regain: come upon after searching; find the location of something that was missed or lost

Other hypernyms of come across include find.

come across (verb)	regain (verb)
be received or understood	get or find back; recover the use of
communicate the intended meaning or impression	come upon after searching; find the location of something that was missed or lost
come together
be perceived in a certain way; make a certain impression
find unexpectedly