liner

Liner is a term with several related but distinct meanings. As a noun, it denotes an inner layer that lines or coats the inside of something. Liners are widely used to provide protection, insulation, or a better fit: fabric or foil linings in containers, rubber liners in machinery, or the inner lining of clothing such as jackets or gloves.

In transportation, a liner is a passenger ship that operates on regular, published routes between ports, as opposed to a tramp steamer that sails opportunistically. Historical liners carried passengers and cargo on long voyages, often with notable amenities; modern usage remains in reference to certain ocean and river routes.

In apparel and textiles, a liner refers to the inner layer of a garment, such as a coat liner or a thermal lining, often made from smooth, insulating, or moisture-wicking fabric. Liners can be removable or integrated into the garment’s construction.

In cosmetics, liner commonly refers to a product used to define facial features, notably eyeliner and lip liner, applied along the edges of the eyelids or lips to create a defined contour.

In packaging, liners are inner layers or coatings inside containers, bags, or cartons, sometimes to provide moisture barriers, prevent leakage, or protect the contents from contact with the outer material.

Other uses include liner notes, the credits and commentary accompanying a musical recording, and the general sense of an inner surface or protective layer in various specialized contexts.