noun

a horizontal bar fixed across the front or back of a motor vehicle to reduce damage in a collision.

she started the car with a jerk and hit the bumper of the car in front

adjective

exceptionally large, fine, or successful.

a bumper crop

abundant,rich,heavy,healthy,bountiful,goodly,large,big,huge,immense,massive,exceptional,unusual,good,excellent,fine,magnificent,lovely,vintage,superabundant,prolific,profuse,copious,profitable,whopping,lank,bounteous,plenteous