Touched heads (4)
I believe the answer is:
nuts
I believe this is a double definition.
'touched' is the first definition.
(both can mean crazy)
'heads' is the second definition.
(I've seen this before)
(Other definitions for nuts that I've seen before include "Mad; fruit" , "Hard shells with edible kernels" , "Crazy (sl.)" , "Crazy (from Brazil?)" , "Stun (anag.)" .)