imitation vs put-on

imitation and put-on both are nouns.

Word	Noun	Adjective	Verb	Adverb
imitation	Yes	Yes	No	No
put-on	Yes	No	No	No

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

imitation: a representation of a person that is exaggerated for comic effect
put-on: 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, send-up, sendup, spoof, takeoff, travesty.

imitation (noun)	put-on (noun)
copying (or trying to copy) the actions of someone else	something intended to deceive; deliberate trickery intended to gain an advantage
something copied or derived from an original	a ludicrous or grotesque act done for fun and amusement
the doctrine that representations of nature or human behavior should be accurate imitations	a composition that imitates or misrepresents somebody's style, usually in a humorous way
a representation of a person that is exaggerated for comic effect

imitation (adjective)	put-on (adjective)
not genuine or real; being an imitation of the genuine article