Lithe, supple (7)
I believe the answer is:
lissome
This clue is a double definition.
'lithe' is the first definition.
(I know that lithe can be written as lissome)
'supple' is the second definition.
(I know that supple can be written as lissome)
(Other definitions for lissome that I've seen before include "Slim, supple, graceful" , "Willowy" , "flexible" , "Thin - supple - graceful" , "Lithe; nimble" .)