ring

A circle.

Example: The students sat in a ring.

A piece of metal in a circle usually worn in the ear or on the finger or toe.

Example: She wore a ring on each finger.

A piece of material with the shape of a circle.

Example: The O-rings went bad on my truck.

A high sound, especially of a telephone.

Example: The ring of the phone woke me up.

The square area between four poles where people fight.

Example: He climbed into the ring, ready to fight.