Person serving in battle on ship essentially lost (9)
I believe the answer is:
sommelier
'person' is the definition.
The answer is an example.
'in battle on ship essentially lost' is the wordplay.
I cannot really see how this works, but
'battle' could be 'somme' (Somme is an example) and 'somme' is found in the answer.
'lost' could be 'l' (abbreviation in sporting league tables) and 'l' is located in the answer.
This explanation may well be incorrect...
'serving' acts as a link.
Can you help me to learn more?
(Other definitions for sommelier that I've seen before include "Expert" , "The wine expert-server in a hotel" , "Restaurant worker" , "Restaurant owner" , "One waits" .)