Gambled on stealing contents of cash cow? (5)
I believe the answer is:
beast
'cow?' is the definition.
(cow is a kind of beast)
'gambled on stealing contents of cash' is the wordplay.
'gambled on' becomes 'bet' (I can't justify this - if you can you should give a lot more credence to this answer).
'stealing' means one lot of letters goes inside another.
'contents of' indicates the central letters (I've seen 'content of' mean this).
The middle letters of 'cash' are 'as'.
'bet' placed around 'as' is 'BEAST'.
Can you help me to learn more?
(Other definitions for beast that I've seen before include "Large animal -- objectionable person" , "Traditional poet" , "Dangerous animal" , "beef?" , "Inhuman person" .)