Credit cards to hold out in photo (7)

I believe the answer is:

plastic

I'm a little stuck... Click here to teach me more about this clue!

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

I cannot understand how the remainder of the clue works.

(Other definitions for plastic that I've seen before include "Credit card - pliable" , "Synthetic substance" , "Credit card; mouldable" , "Compliant" , "means of deferring payment" .)

I've seen this clue in The Telegraph, The Sun and The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.