something worn round the neck, whether for use, ornament, restraint, or identification; as, the collar of a coat; a lady's collar; the collar of a dog.-a ring or cincture.-a collar beam.-the neck or line of junction between the root of a plant and its stem.-an ornament worn round the neck by knights, having on it devices to designate their rank or order.-a ringlike part of a mollusk in connection with esophagus.-a colored ring round the neck of a bird or mammal.-a ring or round flange upon, surrounding, or against an object, and used for restraining motion within given limits, or for holding something to its place, or for hiding an opening around an object; as, a collar on a shaft, used to prevent endwise motion of the shaft; a collar surrounding a stovepipe at the place where it enters a wall. the flanges of a piston and the gland of a stuffing box are sometimes called collars.-an eye formed in the bight or bend of a shroud or stay to go over the masthead; also, a rope to which certain parts of rigging, as dead-eyes, are secured.-a curb, or a horizontal timbering, around the mouth of a shaft.-to seize by the collar.-to put a collar on.