ash bin vs ashcan

ash bin and ashcan both are nouns.

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

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

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

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