1.VerbTo refuel an aircraft while one of its engines is running.
"The plane's APU was broken and the airport didn't have ground starting equipment, so we had to hot refuel the bird - if we'd shut both engines down, we wouldn't have been able to get them started again."
2.NounAn instance of hot refueling.
"Hot refuels require the fueling crew to take great care to avoid getting sucked into the operating engine."