Sort found in sleepy towns all over (4)
I believe the answer is:
type
'sort' is the definition.
(type is a kind of sort)
'in sleepy towns all over' is the wordplay.
'in' indicates a hidden word.
'all over' shows that the letters should be reversed in order.
'epyt' is hidden in the letters of 'sleepy towns'.
'epyt' backwards is 'TYPE'.
'found' acts as a link.
(Other definitions for type that I've seen before include "Print form" , "key" , "Sort, variety" , "get words on to paper?" , "Kind or class as of people" .)