Nervous, jumpy (7)
I believe the answer is:
twitchy
This clue is a double definition.
'nervous' is the first definition.
(I've seen this before)
'jumpy' is the second definition.
(thesaurus)
(Other definitions for twitchy that I've seen before include "Nervous" , "Showing signs of nervousness" , "in a stew" , "Jerky" , "Agitated" .)