Definitions

1. noun

a light or lamp placed on a horse or other animal, especially at night, so as to cast a light ahead

“The cowboy used a jacklight to navigate through the dark forest.”

2. noun

a light or glow on the horizon, especially at night, indicating the presence of a fire or other source of light

“The jacklight on the distant horizon caught their attention.”

3. verb

to provide with a jacklight

“The park ranger had to jacklight the hikers so they could see in the dark.”