Definitions for "Fire mark"
An insignia, attached to the outside of a house, that represented the insurer of the house.
A usually metal symbol place by insurance companies on the buildings that they insure.
A plaque affixed to the wall of a building bearing the name or device of an insurance company and often its policy number, to denote that the building or its contents was insured by that company. Fire marks of the l7th and 18th century were nearly always of lead. Cf. Fire plate.