ash vs residue

ash and residue both are nouns.

Word	Noun	Adjective	Verb	Adverb
ash	Yes	No	Yes	No
residue	Yes	No	No	No

As nouns, residue is a hypernym of ash; that is, residue is a word with a broader meaning than ash:

ash (noun)	residue (noun)
any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus	something left after other parts have been taken away
strong elastic wood of any of various ash trees; used for furniture and tool handles and sporting goods such as baseball bats	matter that remains after something has been removed
the residue that remains when something is burned

ash (verb)	residue (verb)
convert into ashes