Synthetic, mouldable material (7)
I believe the answer is:
plastic
I believe this clue is a double definition.
'synthetic' is the first definition.
(plastic is a synthetic material)
'mouldable material' is the second definition.
(I've seen this before)
(Other definitions for plastic that I've seen before include "Credit cards etc" , "Scalp it badly to make a synthetic material" , "Lips act as a synthetic material" , "Artificial; easily moulded" , "Capable of being moulded" .)