clown vs harlequin

clown and harlequin both are nouns.

Word	Noun	Adjective	Verb	Adverb
clown	Yes	No	Yes	No
harlequin	Yes	No	Yes	No

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

clown: a person who amuses others by ridiculous behavior
harlequin: a clown or buffoon (after the Harlequin character in the commedia dell'arte)

Other hyponyms of clown include fool, jester, motley fool, whiteface, zany.

clown (noun)	harlequin (noun)
a person who amuses others by ridiculous behavior	a clown or buffoon (after the Harlequin character in the commedia dell'arte)
a rude or vulgar fool

clown (verb)	harlequin (verb)
act as or like a clown	variegate with spots or marks