One who might appear before court jester with cape (7)
I believe the answer is:
witness
'one who might appear before court' is the definition.
(as in a witness in a court case)
'jester with cape' is the wordplay.
'jester' becomes 'wit' (both can mean a comical person).
'with' says to put letters next to each other.
'cape' becomes 'ness' (synonyms).
'wit'+'ness'='WITNESS'
(Other definitions for witness that I've seen before include "Testimony - see" , "One who saw an event, may give evidence" , "One sees and reports" , "Spectator" , "One giving evidence" .)