stress vs emphasise

stress is a noun but emphasise is not a noun.

Word	Noun	Adjective	Verb	Adverb
stress	Yes	No	Yes	No
emphasise	No	No	Yes	No

As verbs, stress and emphasise are synonyms defined as:

Other synonyms of stress include accent, accentuate, emphasize, punctuate.

As verbs, emphasise is a hyponym of stress; that is, emphasise is a word with a more specific, narrower meaning than stress:

stress (noun)	emphasise (noun)
the relative prominence of a syllable or musical note (especially with regard to stress or pitch)
(physics) force that produces strain on a physical body
(psychology) a state of mental or emotional strain or suspense
difficulty that causes worry or emotional tension
special emphasis attached to something

stress (verb)	emphasise (verb)
to suffer from stress	to stress, single out as important
to stress, single out as important	give extra weight to (a communication)
put stress on; utter with an accent
test the limits of