residue vs cotton cake

residue and cotton cake both are nouns.

Word	Noun	Adjective	Verb	Adverb
residue	Yes	No	No	No
cotton cake	Yes	No	No	No

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

residue: matter that remains after something has been removed
cotton cake: the solid matter remaining after oil has been pressed from cottonseeds

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

residue (noun)	cotton cake (noun)
something left after other parts have been taken away	the solid matter remaining after oil has been pressed from cottonseeds
matter that remains after something has been removed