joker vs comedian

joker and comedian both are nouns.

Word	Noun	Adjective	Verb	Adverb
joker	Yes	No	No	No
comedian	Yes	No	No	No

As nouns, comedian is a hypernym of joker; that is, comedian is a word with a broader meaning than joker:

joker: a person who enjoys telling or playing jokes
comedian: a professional performer who tells jokes and performs comical acts

Other hypernyms of joker include comic.

joker (noun)	comedian (noun)
a playing card that is usually printed with a picture of a jester	a professional performer who tells jokes and performs comical acts
an inconspicuous clause in a document or bill that affects its meaning in a way that is not immediately apparent	an actor in a comedy
a person who enjoys telling or playing jokes
a person who does something thoughtless or annoying