Aft/æft/ Definition 1 of 2Pro Tip 1/3Nautical Term Used specifically on boats or ships to mean the back part. Hear the engines roar from aft! Pro Tip 2/3Movement Direction Implies moving towards the rear, often against the usual direction. He stumbled aft during the turbulence. Pro Tip 3/3Safety Reference In emergencies, moving aft can mean moving to a safer area. All passengers, please head aft immediately!