File n.
 1. An orderly succession; a line; a row; as: (a) (Mil.) A row of soldiers ranged one behind another; -- in contradistinction to rank, which designates a row of soldiers standing abreast; a number consisting the depth of a body of troops, which, in the ordinary modern formation, consists of two men, the battalion standing two deep, or in two ranks.
 Note: ☞ The number of files in a company describes its width, as the number of ranks does its depth; thus, 100 men in “fours deep” would be spoken of as 25 files in 4 ranks.
 (b) An orderly collection of papers, arranged in sequence or classified for preservation and reference; as, files of letters or of newspapers; this mail brings English files to the 15th instant. (c) The line, wire, or other contrivance, by which papers are put and kept in order.
    It is upon a file with the duke's other letters.   --Shak.
 (d) A roll or list. “A file of all the gentry.”
 2. Course of thought; thread of narration. [Obs.]
    Let me resume the file of my narration.   --Sir H. Wotton.
 File firing, the act of firing by file, or each file independently of others.
 File leader, the soldier at the front of any file, who covers and leads those in rear of him.
 File marching, the marching of a line two deep, when faced to the right or left, so that the front and rear rank march side by side. --Brande & C.  --Indian file, or Single file, a line of people marching one behind another; a single row.  Also used adverbially; as, to march Indian file.
 On file, preserved in an orderly collection; recorded in some database.
 Rank and file. (a) The body of soldiers constituting the mass of an army, including corporals and privates. --Wilhelm. (b) Those who constitute the bulk or working members of a party, society, etc., in distinction from the leaders.