imitation vs sendup

imitation and sendup both are nouns.

Word	Noun	Adjective	Verb	Adverb
imitation	Yes	Yes	No	No
sendup	Yes	No	No	No

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

imitation: a representation of a person that is exaggerated for comic effect
sendup: a composition that imitates or misrepresents somebody's style, usually in a humorous way

Other hyponyms of imitation include mock-heroic, burlesque, lampoon, mockery, parody, pasquinade, put-on, send-up, spoof, takeoff, travesty.

imitation (noun)	sendup (noun)
copying (or trying to copy) the actions of someone else	a composition that imitates or misrepresents somebody's style, usually in a humorous way
something copied or derived from an original
the doctrine that representations of nature or human behavior should be accurate imitations
a representation of a person that is exaggerated for comic effect

imitation (adjective)	sendup (adjective)
not genuine or real; being an imitation of the genuine article