Small amount of glue (3)
I believe the answer is:
dab
'small amount of glue' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dab that I've seen before include "Gently wipe" , "Digital radio" , "A bad sort of little fish" , "A small fish - bad one" , "Small North Atlantic flatfish" .)