Envoy say coming in after hours (6)
I believe the answer is:
legate
'envoy' is the definition.
(I know that legate is a type of envoy)
'say coming in after hours' is the wordplay.
'say' becomes 'eg' (both can mean 'for example').
'coming in' means one lot of letters goes inside another.
'after hours' becomes 'late' (during late hours).
'eg' inserted inside 'late' is 'LEGATE'.
(Other definitions for legate that I've seen before include "papal emissary" , "Official representative" , "Vatican emissary" , "Papal ambassador" , "messenger for the Pope" .)