For the purpose of this question, a 3D game engine is defined as a framework for managing game state and behavior, integrated with 3D-specific middleware (at minimum, a rendering engine). This is based on Wikipedia's definition of a game engine, specialized to 3D while taking note of the second paragraph: A game engine is the software, i.e. some algorithms, solely responsible for the game mechanics and is strictly speaking not the rendering engine. Like e.g. the physics engine, the rendering engine is just middleware. The rendering engine is responsible for the rendering or rather 3D rendering and not for the game mechanics.
The downhaul is a line which is part of the rigging on a sailboat; it applies downward force on a spar or sail. The most common downhaul on a modern sailboat is attached to the spinnaker pole, though this may be referred to as the foreguy in some rigging nomenclature. The term is also commonly applied to the cunningham on the mainsail. In a windsurfing rig, the downhaul is the primary load-bearing line which controls the sail's shape. Modern windsurfing sails incorporate a sleeve for the mast, and therefore do not have a halyard which tensions the top of the sail.
HANK - A metal or nylon clip used to hold the luff of a headsail or staysail to the forestay. TACK - The lower, forward corner of a sail. FOOT - The lowest edge of a sail. CLEW - The lower, aft corner of a fore-and-aft sail, where the leech meets the foot. BROADSEAM - A seam in a sail, in which the edges of neighboring panels are cut in a convex curve, so that when they are sewn together the resulting taper in the panels forces fullness into the sail.