Nervous judge I hear penning note (7)
I believe the answer is:
jittery
'nervous' is the definition.
('jittery' can be a synonym of 'nervous')
'judge i hear penning note' is the wordplay.
'judge' becomes 'j'.
'hear' becomes 'try' ('try' can be a synonym of 'hear').
'penning' is an insertion indicator.
'note' becomes 'te' (**).
'try' enclosing 'te' is 'ttery'.
'j'+'i'+'ttery'='JITTERY'
(Other definitions for jittery that I've seen before include "Nervous" , "Edgy" .)