Soldier on a horse, or ship (7)
I believe the answer is:
trooper
This could be a double definition.
'soldier on a horse' is the first definition.
'trooper' can be an answer for 'soldier' (trooper is a kind of soldier). I am not sure about the 'on a horse' bit.
'ship' is the second definition.
(I've seen this before)
'or' acts as a link.
Can you help me to learn more?
(Other definitions for trooper that I've seen before include "ship" , "Proverbially swearing soldier" , "Cavalryman" , "He swears" , "Private soldier" .)