Pacifier for fool (5)
I believe the answer is:
dummy
This clue is a double definition.
'pacifier' is the first definition.
(I know that pacifier can be written as dummy)
'for fool' is the second definition.
(I've seen this in another clue)
(Other definitions for dummy that I've seen before include "Fool" , "Model of a human being" , "Mock-up; non-working version" , "Mannequin" , "Visible hand of cards" .)