Definition of "jacklight"
(Canada, US) A spotlight or lamp mounted on a car, boat or pole, etc. to aid in hunting.
Quotations
It was a long, low roadster, with a jacklight.
1931, William Faulkner, Sanctuary, Library of America, published 1985, page 19
verb
third-person singular simple present jacklights, present participle jacklighting, simple past and past participle jacklighted or jacklit