Escort a damaged ship (7)
I believe the answer is:
coaster
'ship' is the definition.
(coaster is a type of ship)
'escort a damaged' is the wordplay.
'damaged' indicates anagramming the letters.
'escort'+'a'='escorta'
'escorta' is an anagram of 'COASTER'.
(Other definitions for coaster that I've seen before include "Trading vessel" , "Small ship or beer mat" , "Small mat; cargo ship" , "proceeds with little effort" , "Small table mat" .)