It's used in jelly and adhesives (8)
I believe the answer is:
gelatine
'it's used in jelly and adhesives' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for gelatine that I've seen before include "It's used in jelly and adhesives" , "Animal-based gluey substance used in cooking, photography etc" , "Setting agent" , "Sticky substance obtained from boiled animal tissue" , "Clear edible jelly" .)