Pitter describes the light, quick, tapping sound of many small things hitting a surface. When rain begins to pitter against your bedroom window, you hear those gentle drops landing one after another. When a dog's claws go pitter-patter across a hardwood floor, each nail makes its own tiny click.

The word captures something specific about the sound: it's not one big noise but lots of little ones coming fast. You wouldn't use pitter to describe thunder or a door slamming. It's for delicate, rapid sounds like seeds spilling onto a table, hail bouncing off a car roof, or your little sister's feet running down the hallway early on Christmas morning.

Writers often use pitter-patter together because the two words echo each other and strengthen the feeling of rhythm and repetition. “The rain began to pitter-patter on the tent” helps you almost hear the sound. The word itself sounds like what it describes, which makes it especially fun to say and hear.