Wavy, winding (7)
I believe the answer is:
sinuous
This clue is a double definition.
'wavy' is the first definition.
(synonyms)
'winding' is the second definition.
(I've seen this in another clue)
(Other definitions for sinuous that I've seen before include "Supply bending; wavy" , "Twisting and turning" , "Lithe, supple; curvy" , "Curving in and out" , "Serpentine" .)