Peer docked in good time (4)
I believe the answer is:
earl
'peer' is the definition.
(earl is a kind of peer)
'docked in good time' is the wordplay.
'docked' means to remove the last letter (to dock can mean to remove the tail of an animal).
'in good time' becomes 'early' (being early is arriving in good time).
'early' with its last letter removed is 'EARL'.
(Other definitions for earl that I've seen before include "Countess his wife" , "Sandwich perhaps" , "Titled man" , "Peer (Br.)" , "Essex, say" .)