re-emphasize vs emphasise

re-emphasize and emphasise both are verbs.

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

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

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

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