WordNet
curtain ring
n. a circular ring for holding up a curtain
Wikipedia
Curtain ring
A curtain ring is a small clip designed to hold a curtain in place. As their principal purpose is to hold up curtains of all types, examples of their use can be found on shower curtains and other types of curtains.
Usage examples of "curtain ring".
There was a faint sound in the room behind him, as though a metal curtain ring clicked lightly on a metal rod.
A strand of piano wire emerged from the aperture, and he had fixed a brass curtain ring to the end of it, and taped the ring to the brown leather beside the handle.