a large passenger ship on a regular route

• a large passenger airplane operating scheduled flights

a removable inner layer or cover that lines and protects

• e.g., trash can bag, jacket lining, glove or shoe liner, pantyliner

a replaceable metal sleeve inside an engine cylinder

the printed insert included in a record, tape, or disc package

baseball: a ball hit hard on a straight line

informal: short for eyeliner, a cosmetic for lining eyelids

to fit an engine cylinder with a liner

astrophysics: low-ionization nuclear emission-line region (acronym LINER)