re-emphasise vs emphasize

re-emphasise and emphasize both are verbs.

Word	Noun	Adjective	Verb	Adverb
re-emphasise	No	No	Yes	No
emphasize	No	No	Yes	No

As verbs, emphasize is a hypernym of re-emphasise; that is, emphasize is a word with a broader meaning than re-emphasise:

Other hypernyms of re-emphasise include accent, accentuate, emphasise, punctuate, stress.

re-emphasise (verb)	emphasize (verb)
emphasize anew	to stress, single out as important
	give extra weight to (a communication)