Palace attendant has no time for messenger (7)
I believe the answer is:
courier
'messenger' is the definition.
('courier' can be a synonym of 'messenger')
'palace attendant has no time' is the wordplay.
'palace attendant' becomes 'courtier'.
'has no' is a deletion indicator.
'time' becomes 't'.
'courtier' with 't' taken away is 'COURIER'.
'for' is the link.
(Other definitions for courier that I've seen before include "Person delivering a parcel, say, by motorcycle" , "Dispatch rider" , "guide for tourists" , "Tourist guide" , "Messenger, often on a motorbike" .)