Easily forged credit cards? (7)

I believe the answer is:

plastic

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'credit cards?' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for plastic that I've seen before include "Credit cards etc" , "Artificial; easily moulded" , "Capable of being moulded" , "source of credit" , "Clasp it (anag.)" .)

I've seen this clue in The Telegraph.

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