Origin of fire line
An Americanism dating back to 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for fire line
In the dusk that filled the room above the fire-line, she could not see his face.Kildares of Storm
Eleanor Mercein Kelly
During such periods, Charley would walk back along the fire-line to make sure that the blaze was extinguished behind him.
Then he walked slowly around the burned area, examining it closely, but not stepping within the fire-line.
By the time the fire-line had advanced to the steeper slopes it was one vast U about three miles long.The Rocky Mountain Wonderland
Enos A. Mills
Then together they bore him, now unconscious, slowly down below the first fire-line.Bob Hampton of Placer