wastebin vs ash bin

wastebin and ash bin both are nouns.

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

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

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

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