Left over umpteen umbrellas expected after vacation (6)

I believe the answer is:

unused

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'left over' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for unused that I've seen before include "hadn't been exploited" , "Neither employed nor second-hand" , "Mint, as new" , "Not utilised" , "In mint condition" .)

I've seen this clue in The Telegraph.

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