a Middle English merger of Old English line "cable, rope; series, row, row of letters; rule, direction," and Old French ligne "guideline, cord, string; lineage, descent;" both from Latin linea "linen thread, string, line," from phrase linea restis "linen cord," from fem. of lineus (adj.) "of linen," from linum "linen" (see linen).
Oldest sense is "rope, cord, string;" extended late 14c. to "a thread-like mark" (from sense "cord used by builders for making things level," mid-14c.), also "track, course, direction." Sense of "things or people arranged in a straight line" is from 1550s. That of "cord bearing hooks used in fishing" is from c.1300. Meaning "one's occupation, branch of business" is from 1630s, probably from misunderstood KJV translation of 2 Cor. x:16, "And not to boast in another mans line of things made ready to our hand," where line translates Greek kanon, literally "measuring rod." Meaning "class of goods in stock" is from 1834. Meaning "telegraph wire" is from 1847 (later "telephone wire").
Meaning "policy or set of policies of a political faction" is 1892, American English, from notion of a procession of followers; this is the sense in party line. In British army, the Line (1802) is the regular, numbered troops, as distinguished from guards and auxiliaries. In the Navy (1704, e.g. ship of the line) it refers to the battle line. Lines "words of an actor's part" is from 1882. Lines of communication were originally transverse trenches in siegeworks.
"to cover the inner side of," late 14c., from Old English lin "linen cloth" (see linen). Linen was frequently used in the Middle Ages as a second layer of material on the inner side of a garment. Related: Lined; lining.
late 14c., "to tie with a cord," from line (n.). Meaning "to mark or mark off with lines" is from mid-15c. Sense of "to arrange in a line" is from 1640s; that of "to join a line" is by 1773. To line up "form a line" is attested by 1889, in U.S. football.
The path traced by a moving point.
A thin continuous mark, as that made by a pen, pencil, or brush applied to a surface.
A crease in the skin, especially on the face; a wrinkle.
In anatomy, a long narrow mark, strip, or streak distinguished from adjacent tissue by color, texture, or elevation.
A real or imaginary mark positioned in relation to fixed points of reference.
A border, boundary, or demarcation.
A contour or an outline.
A mark used to define a shape or represent a contour.
Any of the marks that make up the formal design of a picture.
A cable, rope, string, cord or wire.
A general method, manner, or course of procedure.
A manner or course of procedure determined by a specified factor.
An official or prescribed policy.
Ancestry or lineage.
A series of persons, especially from one family, who succeed each other.
In a risky or vulnerable position; at risk, esp deliberately; up for grabs: The whole season's on the line this inning
[1968+; origin unknown; perhaps fr a gambling game where the bet is placed on a line; perhaps fr the commercial slang expression lay (the price or payment) on the line, ''pay, pay up''; perhaps fr the sense of line as separating combatants or duelists]
someone's ass is on the line, the bottom line, chow line, hard line, hot line, in line, in line for, lay it on the line, main line, on line, on the line, out of line, punch line, put one's ass on the line, redline, shoot someone a line, stag line, toe the mark