racer
Concise Oxford English Dictionary © 2008 Oxford University Press:
racer/ˈreɪsə(r)/
▶noun
- 1 an animal or vehicle used for racing.
■ a person who competes in races.
- 2 a harmless fast-moving slender snake. [Coluber constrictor (N. America) and other species.]
- 3 a circular horizontal rail along which the carriage or traversing platform of a heavy gun moves.
'racer' also found in these Oxford entries:

