send vs despatch

send is not a noun while despatch is a noun.

Word	Noun	Adjective	Verb	Adverb
send	No	No	Yes	No
despatch	Yes	No	Yes	No

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

Other hyponyms of send include barge, railroad, dispatch, send off, forward, send on.

send (noun)	despatch (noun)
	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)

send (verb)	despatch (verb)
cause to be directed or transmitted to another place	send away towards a designated goal
transfer
broadcast over the airwaves, as in radio or television
assign to a station
to cause or order to be taken, directed, or transmitted to another place
transport commercially
cause to go somewhere
cause to be admitted; of persons to an institution