residue vs crackling

residue and crackling both are nouns.

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

As nouns, crackling is a hyponym of residue; that is, crackling is a word with a more specific, narrower meaning than residue:

Other hyponyms of residue include greaves, ash, cotton cake, cottonseed cake, dottle, brewer's grain, draff, spent grain.

residue (noun)	crackling (noun)
something left after other parts have been taken away	the sharp sound of snapping noises
matter that remains after something has been removed	the residue that remains after animal fat has been rendered