A structure, usually in the form of a tower, containing signal lights for the guidance of vessels at night, at dangerous points of a coast, shoals, etc. They are usually erected by government, and subject to governmental regulation. Light house board. A commission authorized by congress, consisting of two officers of the navy, two officers of the corps of engineers of the army, and two civilians, together with an officer of the navy and an officer of engineers of the army as secretaries, attached to the office of the secretary of the treasury, at Washington, and charged with superintending the construction and management of light houses, light ships, and other maritime signals for protection of commerce. Abbott.