Whip in The Secret Agent for show (7)
I believe the answer is:
splashy
'whip in the secret agent for show' is the definition.
I can't tell whether this defines the answer.
'whip in the secret agent' is the wordplay.
'whip' becomes 'lash' (synonyms).
'in the' means one lot of letters goes inside another.
'secret agent' becomes 'spy' (spy is a kind of secret agent).
'lash' placed into 'spy' is 'SPLASHY'.
Can you help me to learn more?
(Other definitions for splashy that I've seen before include "catching crabs?" , "Ostentatious" .)