Shakespearean pledged something of interest in speech (5)
I believe the answer is:
fined
'shakespearean' is the definition.
Although both the answer and definition are adjectives, I cannot see how one could define the other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for fined that I've seen before include "Fed in (anag.)" , "Mulcted" , "Ordered to pay penalty" , "Imposed financial penalty on" .)