The term SURF'S SOUND is composed of two crossword solutions, ROAR (4 letters) and ROTE (4 letters). ROAR is the sound made by a large animal, such as a lion or bear, and is also used to describe a loud, deep sound. ROTE is a memorization technique that involves repeating something over and over until it is learned. Together, these two words can be used to describe the sound of the ocean surf, which is often a loud ROAR that is repeated in a rhythmic pattern.