If you've been working hard and living thriftily for months on end, give yourself a treat: take the night off and go out to dinner and a movie.
One sense of treat has to do with pleasures and special occasions. You might treat your mother to a pedicure, or give your dog a tasty treat. Treat can also mean "to carry on negotiations," (the meaning that feeds into treaty), or "to take care of." A doctor treats your illness with medication. If you treat a boy as an adult, that means you act as though he is one, even if he's only 16. Treat him carefully!