Farewell from man-servant short of time (4)
I believe the answer is:
vale
'farewell' is the definition.
(I've seen this before)
'man-servant short of time' is the wordplay.
'man-servant' becomes 'valet' (I've seen this before).
'short of' indicates named letters should be taken away.
'time' becomes 't' (abbreviation).
'valet' with 't' taken away is 'VALE'.
'from' is the link.
(Other definitions for vale that I've seen before include "Cheers" , "Valley" , "Trough between ridges" , "Long depression containing a river" , "Maida -, N. London area; farewell (archaic)" .)