write-down vs write down

write-down is a noun but write down is not a noun.

Word	Noun	Adjective	Verb	Adverb
write-down	Yes	No	No	No
write down	No	No	Yes	No

write-down (noun)	write down (noun)
(accounting) reduction in the book value of an asset

write-down (verb)	write down (verb)
	reduce the estimated value of something
	put down in writing; of texts, musical compositions, etc.