Man perhaps is extremely late (4)
I believe the answer is:
isle
'man perhaps' is the definition.
(Isle of Man is an example)
'is extremely late' is the wordplay.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'late' with its centre taken out is 'le'.
'is'+'le'='ISLE'
(Other definitions for isle that I've seen before include "what Donne implied he wasn't" , "Eg, Sheppey" , "-- of Ely, Dogs, Man" , "small piece of land" , "one ringed in the main?" .)