Dictionary
clock•er
Pronunciation: (klok'ur), [key]—
n.
1. a person who times racehorses during tryouts to determine their speed.
2. an official who times a race.
3. a person who maintains a record of the flow of traffic, as of visitors to a museum.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.