bell jar vs bell glass

bell jar and bell glass both are nouns.

Word	Noun	Adjective	Verb	Adverb
bell jar	Yes	No	No	No
bell glass	Yes	No	No	No

As nouns, bell jar and bell glass are synonyms defined as:

bell jar and bell glass: a bell-shaped glass cover used to protect and display delicate objects or to cover scientific apparatus or to contain gases

bell jar (noun)	bell glass (noun)
a bell-shaped glass cover used to protect and display delicate objects or to cover scientific apparatus or to contain gases	a bell-shaped glass cover used to protect and display delicate objects or to cover scientific apparatus or to contain gases