Locks, tresses (4)
I believe the answer is:
hair
This clue is a double definition.
'locks' is the first definition.
(locks can mean hair)
'tresses' is the second definition.
(I've seen this in another clue)
(Other definitions for hair that I've seen before include "Barber's speciality; musical" , "Barnet" , "Red face powder" , "It grows from the skin" , "Fibre; small extent" .)