Writhe, squirm (7)
I believe the answer is:
wriggle
I believe this clue is a double definition.
'writhe' is the first definition.
(I know that writhe can be written as wriggle)
'squirm' is the second definition.
(synonyms)
(Other definitions for wriggle that I've seen before include "Move like worm" , "Twist to and fro" , "Squirm" , "Move writhingly" , "Move with short twisting jerks" .)