Feverish girl with nervous twitch (7)
I believe the answer is:
frantic
'feverish' is the definition.
(thesaurus)
'girl with nervous twitch' is the wordplay.
'girl' becomes 'fran' (**).
'with' says to put letters next to each other.
'nervous twitch' becomes 'tic' (I've seen this before).
'fran'+'tic'='FRANTIC'
(Other definitions for frantic that I've seen before include "Phrenetic" , "Excessively agitated" , "very worried" , "not collected!" , "At the end of one's tether" .)