Lassie, with a capital L, is a famous collie dog: the main character in seven films made between 1943 and 1951, and later in television programmes. She is brave and clever, and she keeps saving people — especially the family she lives with — from rivers, mines, storms, and other trouble. Children in many countries grew up thinking of a rough-coated brown-and-white dog when they heard the name. People sometimes stretch it and call any loyal rescue dog “a Lassie,” but the name itself is that one character. Though actually the word under the name is just Scottish lassie, “little girl,” because the dog is female; the films turned a pet name into a proper name. Write Lassie for the dog on screen; lassie with a small l is still an ordinary Scottish word for a girl.