The term 'small wave' can be described by two crossword solutions: RIPPLE (6 letters) and WAVELET (7 letters). A RIPPLE is a small wave on the surface of a body of water, usually caused by a disturbance such as a stone being thrown into the water. Wavelets are small, localized waves that travel through a medium, such as sound or light. They are often used to describe the behavior of waves in a confined space, such as a pond or lake.