dustbin vs ash bin

dustbin and ash bin both are nouns.

Word	Noun	Adjective	Verb	Adverb
dustbin	Yes	No	No	No
ash bin	Yes	No	No	No

As nouns, dustbin and ash bin are synonyms defined as:

Other synonyms of dustbin include ash-bin, ashbin, ashcan, garbage can, trash barrel, trash bin, trash can, wastebin.

dustbin (noun)	ash bin (noun)
a bin that holds rubbish until it is collected	a bin that holds rubbish until it is collected