Bishop leaving rubbish in lock-up? (6)

I believe the answer is:

garage

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

'lock-up?' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for garage that I've seen before include "Building for vehicle" , "Where car is housed" , "Structure for automobiles" , "Car's home (or hospital?)" , "Attachment to the house" .)

I've seen this clue in The Telegraph.

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