Disappear after pocketing a diamond in an adventure (8)

I believe the answer is:

escapade

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'an adventure' is the definition.
('escapade' can be a synonym of 'adventure')

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for escapade that I've seen before include "Jolly jape" , "daring exploit" , "Risky adventure" , "Wild and exciting undertakings" , "Risky venture" .)

I've seen this clue in The Hindu.

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