Egg in spoon, I think (3)
I believe the answer is:
nit
'egg' is the definition.
(nit is a kind of egg)
'in spoon i think' is the wordplay.
'in' indicates a hidden word.
'NIT' is hidden in the letters of 'spoon i think'.
(Other definitions for nit that I've seen before include "Louse-egg" , "Hair louse" , "Louse; fool" , "Louse's egg; idiot" , "Muggins" .)