pertain

Picture a legal document in medieval England: when something “pertained” to you, it was not merely vaguely relevant—it belonged within your legal orbit. The word arrived in the early 14th century through Old French partenir, carrying Latin pertinēre, a compound built from per, “through,” and tenēre, “to hold.” The image is wonderfully physical: something held through toward a matter, reaching into its proper territory. That holding root also gives us tenure, tenant, retain, contain, and tenacious—the same family keeps showing up whenever possession or grip is involved. Do not confuse the separate English number ten with this ten element; the number comes from a different Indo-European root, while pertain’s Latin tenēre is about holding. When a detail pertains to an argument, it has crossed the threshold and found its rightful place there—an old legal grip disguised as an ordinary word.