Wherein, sheepishly, to give up playing cards? (4)

I believe the answer is:

fold

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'give up playing cards?' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.

I can't explain the remainder of the clue.

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(Other definitions for fold that I've seen before include "Sheep pen; disintegrate" , "enclosure" , "Congregation; (firm) go bankrupt" , "Collapse; bend in half" , "Cease trading" .)

I've seen this clue in the Evening Standard.

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