someone who drives racing cars at high speeds
"The young racer adjusted his helmet before speeding out of the garage to join the track."
a fast car that competes in races
"The sleek racer zoomed around the track, leaving all other competitors far behind."
an animal that races
"The greyhound is a fast racer that loves to chase balls around the garden."
slender fast-moving North American snakes
"The racer slithered quickly across the warm pavement in search of a cool spot to rest."
Someone who takes part in a race.
"The new racer lined up at the starting gate, eager to prove his speed against the competition."
In plain English: A racer is someone who competes to be the fastest person or vehicle in a competition.
"My neighbor is always talking about his new toy racer that zooms across the floor."
Racer is formed by adding the suffix "-er" to the word race and was first recorded in English in 1648. The term originally described someone or something that engages in racing, a meaning it has retained ever since.