to make the form, nature, content, future course, etc., of (something) different from what it is or from what it would be if left alone: to change one's name; to change one's opinion; to change the course of history.
to transform or convert (usually followed by into): The witch changed the prince into a toad.
to substitute another or others for; exchange for something else, usually of the same kind: She changed her shoes when she got home from the office.
to give and take reciprocally; interchange: to change places with someone.
to transfer from one (conveyance) to another: You'll have to change planes in Chicago.