Prison time accepted by Wimbledon champ (8)

I believe the answer is:

alcatraz

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'prison' is the definition.
(former US prison)

I can't explain the remainder of the clue.

(Other definitions for alcatraz that I've seen before include "Notorious US prison" , "Island in San Francisco Bay,once a prison" , "Federal prison in California, 1934-63" , "US island of a former maximum-security prison" , "Once dreaded prison in San Francisco Bay" .)

I've seen this clue in The Times.

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