Money order spoken for by vet or E European? (6)

I believe the answer is:

cheque

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

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

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

(Other definitions for cheque that I've seen before include "means of transferring funds" , "Signed money order" , "A payment order form" , "Written document authorising payment to recipient" , "Method of payment" .)

I've seen this clue in 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.