accent vs play down

accent is a noun but play down is not a noun.

Word	Noun	Adjective	Verb	Adverb
accent	Yes	No	Yes	No
play down	No	No	Yes	No

As verbs, play down is a hyponym of accent; that is, play down is a word with a more specific, narrower meaning than accent:

accent (noun)	play down (noun)
the relative prominence of a syllable or musical note (especially with regard to stress or pitch)
distinctive manner of oral expression
a diacritical mark used to indicate stress or placed above a vowel to indicate a special pronunciation
the usage or vocabulary that is characteristic of a specific group of people
special importance or significance

accent (verb)	play down (verb)
put stress on; utter with an accent	understate the importance or quality of
to stress, single out as important