Some material is somewhat supple (6)
I believe the answer is:
lissom
'supple' is the definition.
(I know that supple can be written as lissom)
'some material is somewhat' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'LISSOM' is hidden in the letters of 'material is somewhat'.
(Other definitions for lissom that I've seen before include "Gracefully slim and supple" , "Limber" , "Lithe and flexible" , "'Lithe, supple (6)'" , "Supple or agile" .)