Definitions

1. noun

A person who is paid to monitor a clock or a time-keeping device to ensure its accuracy and to update it.

“The company hired a clocker to check the clock in the bank lobby every day.”

2. noun

A person who is paid to bet on horse races, especially to place bets on long shots.

“He made a living as a clocker at the local racetrack for years.”

3. verb

To bet on a long shot in a horse race, especially for the purpose of profiting from the subsequent bets placed by other people.

“He clocked a big bet on the underdog horse and won a lot of money.”