peanut gallery vs upper balcony

peanut gallery and upper balcony both are nouns.

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

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

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

Other synonyms of peanut gallery include family circle, second balcony.

peanut gallery (noun)	upper balcony (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)