Scream for the old legal case (4)
I believe the answer is:
yell
'scream' is the definition.
('yell' can be a synonym of 'scream')
'the old legal case' is the wordplay.
'the old' becomes 'ye'.
'case' says to hollow out the word (remove centre letters).
'legal' with its centre taken out is 'll'.
'ye'+'ll'='YELL'
'for' is the link.
(Other definitions for yell that I've seen before include "roar" , "Loud sharp cry" , "Loud cry; rhymes with collapsed" , "Shout loudly" , "Call out" .)