The term 'IT MAKES A WAVE' can be solved by the four-letter word 'SINE'. SINE is a mathematical function that describes a smooth, repetitive oscillation. It is often used to model periodic phenomena such as sound and light waves. In mathematics, the SINE of an angle is the ratio of the length of the opposite side to the length of the hypotenuse in a right triangle. In physics, SINE waves are used to describe the oscillations of electric and magnetic fields.