bumper

n. [ A corruption of bumbard, bombard, a large drinking vessel. ] 1. A cup or glass filled to the brim, or till the liquor runs over, particularly in drinking a health or toast. [ 1913 Webster ]

He frothed his bumpers to the brim. Tennyson. [ 1913 Webster ]

2. A covered house at a theater, etc., in honor of some favorite performer. [ Cant ] [ 1913 Webster ]

n. 1. That which bumps or causes a bump. [ 1913 Webster ]

2. Anything which resists or deadens a bump or shock, such as a metal or rubber rim extending from an object; a buffer. [ 1913 Webster ]

3. Specifically: (Motor vehicles) A protective guard device, usually of metal or rubber, attached horizontally to the front or rear of the frame of a vehicle, designed to resist or deaden a bump or shock, and to prevent damage to the main frame of the vehicle in low-velocity collisions. [ PJC ]