Compass: The navigational compass was… | etymologist.ai
compass
/ˈkʌmpəs/·noun·c. 1290–1300, Middle English 'compas' in the sense of a circular arc or limit; mariner's compass sense attested by c. 1380 (Chaucer)·Established
Origin
From Medieval Latin compassare (to step around), via Old French compas, the word originally named a circle-drawing tool; the magnetic navigation instrument inherited the name because it, too, is a circular, measured device — while the older sense of enclosed range still survives in music and formal speech.
Definition
An instrument for determining cardinal directions, typically consisting of a magnetised needle pointing toward magnetic north; also a V-shaped drawing instrument used to trace circles or measure distances.
The Full Story
Old French13th–14th centurywell-attested
TheEnglish word 'compass' entered Middle English from Old French 'compas', meaning a circle, a pair of dividers, or a measured space. The Old Frenchword derives from the Vulgar Latin verb *compassare, meaning 'to pace out' or 'to measure by steps', a compound of the Latin prefix com- (together, with) and passus (a step, a pace), from the past participle of pandere (to spread, to stretch out). The ultimate PIEroot is *peth₂- (to spread, to stretch, to extend flat
Did you know?
The navigational compass was almost certainly named after the drawing compass, not the other way around — and for centuries both senses coexisted with a third: the full range of a singing voice. In Spanish, 'compás' is still the primary word for musical beat and time signature, a living fossil of the original sense of com- + passus: stepping around together, in measured circles.
Latin patere (to lie open), Greek petannynai (to spread out), and the English word 'fathom'. The Vulgar Latin *compassare gave Old French 'compasser' (to measure, to go around in a
dial. The earliest English attestations appear in late 13th-century texts in the sense of a circular arc or limit, as well as the mathematical drawing instrument. By the mid-14th century, Chaucer used 'compass' to describe the mariner's magnetic instrument. The meaning extended naturally from the idea of measuring or encompassing a circular space to denoting an instrument that points in all cardinal directions. The figurative senses ('within the compass of', meaning within the scope or range) followed by the 15th century. The cognate Latin passus also gives English 'pace', 'pass', 'passage', 'trespass', and 'surpass'. Key roots: *peth₂- (Proto-Indo-European: "to spread, to stretch out, to extend flat"), passus (Latin: "a step, a pace; literally 'a stretching out of the legs'"), com- (Latin: "together, with, completely (intensifying prefix from PIE *kom)").