Crossword Genius

Unstable gambling den? (5,2,5)

Ross

I believe the answer is:

house of cards

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'unstable gambling den?' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

This is all the clue.

Can you help me to learn more?

(Other definitions for house of cards that I've seen before include "building that might fall over" , "Flimsy structure" , "Unstable scheme" .)

I've seen this clue in The Globe and Mail.
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