The term 'On the Liner' is a phrase used to describe someone who is on board a ship or boat. It is often used to refer to passengers, crew members, and other personnel who are on board a vessel. The term can also be used to refer to those who are working on the ship, such as engineers, mechanics, and other personnel. The crossword solution for this term is 'ABOARD', which is a six-letter word meaning to be on board a vessel.