Really top spies caught by pirate (5,5,3)
I believe the answer is:
knock spots off
'really top' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'spies caught by pirate' is the wordplay.
'spies' becomes 'spots' ('spot' can be a synonym of 'spy').
'caught by' is an insertion indicator.
'pirate' becomes 'knock off' (I've seen this before).
'spots' put within 'knockoff' is 'KNOCK SPOTS OFF'.
Can you help me to learn more?
(Other definitions for knock spots off that I've seen before include "better by miles" , "Show superiority" .)