Liner/ˈlaɪnər/ Definition 1 of 4Pro Tip 1/2Scheduled Routes Used for vehicles on a fixed timetable and route, not occasional or random trips. The liner departs every Thursday at 9 PM. Pro Tip 2/2Comfort and Luxury Often implies larger, more luxurious vessels or planes with many amenities. Traveling on an ocean liner offers a luxurious experience at sea.