response vs rejoinder

response and rejoinder both are nouns.

Word	Noun	Adjective	Verb	Adverb
response	Yes	No	No	No
rejoinder	Yes	No	No	No

As nouns, rejoinder is a hyponym of response; that is, rejoinder is a word with a more specific, narrower meaning than response:

response: the speech act of continuing a conversational exchange
rejoinder: a quick reply to a question or remark (especially a witty or critical one)

Other hyponyms of response include counterblast, non sequitur, comeback, counter, replication, retort, return, riposte, echo, answer.

response (noun)	rejoinder (noun)
a bodily process occurring due to the effect of some antecedent stimulus or agent	a quick reply to a question or remark (especially a witty or critical one)
the manner in which an electrical or mechanical device responds to an input signal or a range of input signals	(law) a pleading made by a defendant in response to the plaintiff's replication
the speech act of continuing a conversational exchange
a statement (either spoken or written) that is made to reply to a question or request or criticism or accusation
the manner in which something is greeted
a phrase recited or sung by the congregation following a versicle by the priest or minister
a result