Nervous in court, cramped (7)
I believe the answer is:
uptight
'nervous' is the definition.
('uptight' can be a synonym of 'nervous')
'in court cramped' is the wordplay.
'in court' becomes 'up'.
'cramped' becomes 'tight' (I've seen this before).
'up'+'tight'='UPTIGHT'
(Other definitions for uptight that I've seen before include "Irritated" , "Jumpy" , "Unable to express one's feelings" , "Ill at ease" , "Informally, nervously tense and anxious" .)