The term 'make higher' can be expressed in two ways: 'HEIGHTEN' (8 letters) and 'RAISE' (5 letters). Both words refer to the act of increasing something, usually in terms of height or level. HEIGHTEN is a more formal word, while RAISE is more commonly used in everyday language. Both words can be used to describe the action of making something higher, such as raising the volume of a song or heightening the stakes in a game.