Recover from unfinished excursion nursed by old official (8)
I believe the answer is:
retrieve
'recover' is the definition.
(I know that recover can be written as retrieve)
'unfinished excursion nursed by old official' is the wordplay.
'unfinished' means to remove the last letter.
'excursion' becomes 'trip' (a trip is an excursion or outing).
'nursed by' is an insertion indicator.
'old official' becomes 'reeve' (historical type of legal official).
'trip' with its final letter taken away is 'tri'.
'tri' inserted within 'reeve' is 'RETRIEVE'.
'from' is the link.
(Other definitions for retrieve that I've seen before include "Get back (lost item)" , "Revere it to get back" , "Recover" , "Regain or fetch" , "Win back" .)