write up vs news

write up and news both are nouns.

Word	Noun	Adjective	Verb	Adverb
write up	Yes	No	Yes	No
news	Yes	No	No	No

As nouns, news is a hypernym of write up; that is, news is a word with a broader meaning than write up:

write up (noun)	news (noun)
a short account of the news	the quality of being sufficiently interesting to be reported in news bulletins
	information about recent and important events
	information reported in a newspaper or news magazine
	a program devoted to current events, often using interviews and commentary
	informal information of any kind that is not previously known to someone

write up (verb)	news (verb)
bring to public notice by writing, with praise or condemnation
put into writing; write in complete form