jester vs merry andrew

jester and merry andrew both are nouns.

Word	Noun	Adjective	Verb	Adverb
jester	Yes	No	No	No
merry andrew	Yes	No	No	No

As nouns, merry andrew is a hypernym of jester; that is, merry andrew is a word with a broader meaning than jester:

jester: a professional clown employed to entertain a king or nobleman in the Middle Ages
merry andrew: a person who amuses others by ridiculous behavior

Other hypernyms of jester include buffoon, clown, goof, goofball.

jester (noun)	merry andrew (noun)
a professional clown employed to entertain a king or nobleman in the Middle Ages	a person who amuses others by ridiculous behavior