A mark, a rope, and a row
In modern English, line does an unusual amount of work. It names the stroke a pen leaves, the cord a builder stretches, the people waiting at a counter, a family stretching back through generations, a trade someone works in, a telephone connection, and a sentence an actor has to remember. Those uses look scattered until they are set beside an older picture: a thin length of flax. Continuity, a path you can follow, a cut between two sides — the geometry came later. The fiber came first.
Two routes that met in Middle English
The origin of the word line is not a single borrowing and not a single native heirloom. Middle English inherited Old English līne, already a cable or rope, a series or row, a rule or a direction. In the same centuries it also took in Old French ligne (Anglo-French also has lingne): a guideline, a cord, a string, and, importantly, lineage or descent. The two forms collapsed into one English noun.
How the Old English half arrived is the point where dictionaries part company. Some treat līne as a word inherited inside Germanic, built on the old name for flax. Others derive both the English and the French nouns from Latin līnea. Germanic relatives with the same everyday sense of a cord or rope — Dutch lijn, German Leine, Old Norse lina — are often placed on that Latin path as well. Spanish and Italian keep the learned shape linea. The Oxford English Dictionary, in a short account of the noun, still calls it a Germanic inheritance. The disagreement is real: did English first meet the word as a farm-and-rope term of its own, or as a Latin name that had already spread through the North Sea languages? By the time Middle English is thick on the ground, speakers were not keeping two nouns. They had one.
Flax, linen, and a Latin adjective
Latin līnea did not begin as a geometric idea. It was a linen thread or string, and also a plumb-line. The form is the feminine of līneus, an adjective meaning made of linen, from līnum, flax or linen cloth. In older phrasing the noun is a shortening of something like līnea restis, a linen cord; the cloth-word then stood alone. That is why line and linen still belong to the same household. Old English līn named the plant and the fabric. The later verb that means to put a covering on the inner side of a coat comes from that cloth, not from the drawn mark.
Greek linon names the same plant. A reconstructed ancestral form līno- is sometimes offered, and some accounts set Old English līne under a Proto-Germanic flaxen cord. Flax-words around the Mediterranean may also be older loans from a language we cannot recover. Flax was grown in Europe early enough that a shared inheritance is possible, but a clear match in Indo-Iranian is missing, which makes a local source more plausible. English does not need that last layer settled. What can be seen without guesswork is the chain from plant to thread to mark.
From a measuring cord to a drawn stroke
The oldest English sense is physical. A line is rope, cable, the cord a carpenter or mason uses to take a length or to set work true. From that tool, in the fourteenth century, the meaning stretches to a thread-like mark on a surface, and to a track, a course, or a direction. A county boundary or other limit is later still, from the end of the sixteenth century. The mathematical sense of length without breadth belongs to the mid-sixteenth. A crease in a face or a palm is recorded in the same century. The equator as the line is a little later.
People or things standing in a straight row appear in the 1550s. British English later preferred queue for a waiting file, but the row sense is not an American afterthought; it is in English writers early. A fishing line with hooks is already around 1300, still close to the rope. A line of kings or of descendants is late fourteenth century, helped by the French sense of lineage: a descent you can follow as if it were a thread.
Other extensions keep the same image of a continuous run. Occupation, or a branch of business, is seventeenth century. One cautious explanation ties that sense to a biblical rendering in which a Greek word for a measuring rod or a limit was translated as line, and then read as a sphere of work. Goods a merchant keeps in stock, telegraph and later telephone wires, a run of coaches or ships, a stretch of railway, and a political party line all ride the metaphor of a path that holds or a rule that people walk. The slang line that means smooth, deceptive talk is a worn-down cousin of the political sense: a set of claims a faction repeats.
Army English used the line for regular numbered infantry as against guards or militia. Navy English used it for the battle line, which is why a ship of the line stands in that formation rather than drawing a mark.
A second verb from the same plant
English also has a verb line that does not mean to draw. From the late fourteenth century it means to cover the inner side of a garment. That verb comes from Old English līn, linen cloth, because medieval clothes were often faced on the inside with linen. Filling the insides of something — a box, a pocket, a stomach — is a later widening of the same idea.
A different verb, formed from the noun, first meant to tie with a cord. By the mid-fifteenth century it could mean to mark something off with lines. Arranging people in a row is seventeenth century and at first military. So the language keeps two verbs that look identical: one from flax cloth on the inside of a coat, one from the cord that became a stroke.
What still shows through
If one detail holds the family together, it is the linen. A line was first a flaxen string. German Leine is still a leash or a rope. French ligne still names both a stroke on a page and a line of descent. When a tailor lines a coat, the verb is not a metaphor taken from geometry; it is the old cloth going on the inner face. The thin mark in a notebook is a later shadow of that thread.