Related Clues:

• One used to a cooler environment?
• Old lag with trousers on, as Spooner might have put it?
• Old fool -- one whose time is over
• I've spent my time working with former head of classics
• Prisoner who was 90 kept in a very long time
• Former jailbird
• "Avian" for whom flight is often futile
• Halfway house resident
• Old time-server is political turncoat perhaps
• Convict, inmate
• Convict Jack, having false alibi, by the way
• One's got out of jail as a political defector?
• Parolee, e.g
• One on parole
• Prior prisoner, for short