fire 1. to travel over a specified route to prevent, detect, and suppress fires 2. to go back and forth vigilantly over a length of control line during or after construction to prevent breakovers, suppress spot fires, and extinguish overlooked hot spots 3. to vigilantly check a fireline following mop-up until the fire is extinguished or considered safe from the danger of escape 4. a person or group of persons who carry out patrol actions —see fire guard This definition last updated 07/23/2008