a mechanical device consisting of bars at either end of a vehicle to absorb shock and prevent serious damage
"The driver slammed on the brakes just in time to avoid crashing into the other car's front bumper."
Someone or something that bumps.
"The bumper on his car is designed to absorb impacts and protect the vehicle from damage when someone or something bumps into it."
In plain English: A bumper is a thick piece of padding attached to the front and back of a car to stop it from getting damaged when you crash into something.
"The car had small metal bumpers on both ends to protect its body from damage in minor accidents."
Usage: As a noun, bumper refers specifically to the large metal bar attached to the front and rear of a vehicle for protection during collisions. Do not confuse this with the adjective form meaning "filled to capacity," which describes containers like silos rather than car parts.
To drink from the vessels called bumpers.
"The guests raised their glasses to make a toast by drinking from the large silver bumpers."
In plain English: To bump is to hit something with your body, usually by accident while moving quickly.
"The bumper hit the wall and bounced back hard."
Large; filled to the bumpers at the top of a silo.
"The old grain elevator was bumper full after the harvest, so heavy that the wooden supports groaned under the weight."
In plain English: Bumper describes something that is very large and impressive, usually referring to an unusually big amount of food or money.
"The bumper car ride was so fun that we kept crashing into each other again and again."
The word bumper is formed by adding the suffix -er to the verb bump. It originally referred to a device attached to vehicles or furniture that prevents them from hitting something else when they move too close.