upper balcony vs peanut gallery

upper balcony and peanut gallery both are nouns.

Word	Noun	Adjective	Verb	Adverb
upper balcony	Yes	No	No	No
peanut gallery	Yes	No	No	No

As nouns, upper balcony and peanut gallery are synonyms defined as:

upper balcony and peanut gallery: rearmost or uppermost area in the balcony containing the least expensive seats

Other synonyms of upper balcony include family circle, second balcony.

upper balcony (noun)	peanut gallery (noun)
rearmost or uppermost area in the balcony containing the least expensive seats	rearmost or uppermost area in the balcony containing the least expensive seats
	(figurative) people whose criticisms are regarded as irrelevant or insignificant (resembling uneducated people who throw peanuts on the stage to express displeasure with a performance)