write up vs despatch

write up and despatch both are nouns.

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

As nouns, despatch is a hyponym of write up; that is, despatch is a word with a more specific, narrower meaning than write up:

Other hyponyms of write up include newsletter, newssheet, bulletin, communique, dispatch, urban legend, exclusive, scoop.

write up (noun)	despatch (noun)
a short account of the news	the act of sending off something
	killing a person or animal
	the property of being prompt and efficient
	an official report (usually sent in haste)

write up (verb)	despatch (verb)
bring to public notice by writing, with praise or condemnation	send away towards a designated goal
put into writing; write in complete form