TAN'GENT, noun [Latin tangens, touching. See Touch.] In geometry, a right line which touches a curve, but which when produced, does not cut it. In trigonometry, the tangent of an arc, is a right line touching the arc at one extremity, and terminated by a second passing through the other extremity.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI