Man needing time to leave prison (3)
I believe the answer is:
sir
'man' is the definition.
(sir is a kind of man)
'time to leave prison' is the wordplay.
'time' becomes 't' (abbreviation).
'to leave' is a deletion indicator.
'prison' becomes 'stir' (informal term for prison).
'stir' with 't' taken out is 'SIR'.
'needing' acts as a link.
(Other definitions for sir that I've seen before include "Honorary male title" , "Gentleman's form of address" , "Form of address for a knight" , "Honourable title" , "Title of Kt or Bart" .)