Noun
A passive fire protection product used in heating, ventilation, and air conditioning ducts.
A damper which closes off an air duct automatically in the event of fire so as to restrict the passage of fire and smoke.
(historical, archaic, mining) A mine worker who detects and clears a mineshaft of firedamp by intentionally burning or blowing it up.
Jack is a former fire damper who was injured in an explosion.