function: the actions and activities assigned to or required or expected of a person or group
duty: work that you are obliged to perform for moral or legal reasons
metacenter: (shipbuilding) the point of intersection between two vertical lines, one line through the center of buoyancy of the hull of a ship in equilibrium and the other line through the center of buoyancy of the hull when the ship is inclined to one side; the distance of this intersection above the center of gravity is an indication of the stability of the ship