1. a collar used to restrain or identify a dog.
2. Informal.a close-fitting necklace, as a wide band covered with or composed of precious or semiprecious stones; choker.
3. Slang.a collar of the type worn by some clergymen, priests, etc., having the opening at the back; clerical collar.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.