They're played for money (5)

I believe the answer is:

notes

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

'for money' is the definition.
(I've seen this before)

I don't understand how the remainder of the clue works.

(Other definitions for notes that I've seen before include "Doh, re, mi, ..." , "Written comments" , "Short written messages" , "Memos; observes" , "Paper money" .)

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

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