A lap timer is a device or feature that tracks the time it takes for someone or something to complete a lap or a round, like in a race. It's used to measure the speed and performance of the person or object. Full definition
The radio is replaced by a lightweight cover that can be configured to mount the included lap timer. (thetorquereport.com)
The navigation system shows a combined display with lap timer and navigation information for the racetrack being driven. (thetorquereport.com)
The BMW M4's, Cadillac ATS - V's and Lexus RC F's digital displays may spend more time in lap timer, g - force and sport tachometer modes than in fuel - economy mode, but that didn't stop us from taking the three on a mileage drive to determine a fuel - economy winner. (cars.com)