postpone vs respite

postpone is not a noun while respite is a noun.

Word	Noun	Adjective	Verb	Adverb
postpone	No	No	Yes	No
respite	Yes	No	Yes	No

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

postpone: hold back to a later time
respite: postpone the punishment of a convicted criminal, such as an execution

Other hyponyms of postpone include call, hold, suspend, probate, reprieve.

postpone (noun)	respite (noun)
	a pause from doing something (as work)
	the act of reprieving; postponing or remitting punishment
	an interruption in the intensity or amount of something
	a (temporary) relief from harm or discomfort
	a pause for relaxation

postpone (verb)	respite (verb)
hold back to a later time	postpone the punishment of a convicted criminal, such as an execution