Something heard in court certain to give joy (8)
I believe the answer is:
pleasure
'joy' is the definition.
(I know that joy can be written as pleasure)
'something heard in court certain' is the wordplay.
'something heard in court' becomes 'plea' (I've seen this in another clue).
'certain' becomes 'sure' (synonyms).
'plea'+'sure'='PLEASURE'
'to give' is the link.
(Other definitions for pleasure that I've seen before include "A repulse (anag.)" , "contentment" , "entertainment" , "diversion" , "Enjoyment, happiness" .)