• synonyms


[see-kant, -kuh nt]
  1. Geometry. an intersecting line, especially one intersecting a curve at two or more points.
  2. Trigonometry.
    1. (in a right triangle) the ratio of the hypotenuse to the side adjacent to a given angle.
    2. (originally) a line from the center of a circle through one extremity of an arc to the tangent from the other extremity.
    3. the ratio of the length of this line to that of the radius of the circle; the reciprocal of the cosine of a given angle or arc. Abbreviation: sec
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  1. cutting or intersecting, as one line or surface in relation to another.
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Origin of secant

1585–95; < Latin secant- (stem of secāns, present participle of secāre to cut), equivalent to sec- verb stem (see saw1) + -ant- -ant
Related formsse·cant·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for secant

Historical Examples of secant

  • The complement of the logarithm of a sine, tangent, or secant.

    The Sailor's Word-Book

    William Henry Smyth

  • Secant equals one over cosine—um-m-m-m—one point oh three five.

    Skylark Three

    Edward Elmer Smith

  • Every ray through S1 or S2 which is not a secant determines one of them.

  • That which is made by a right line, whether tangent or secant, with the circumference of a circle.

    The Sailor's Word-Book

    William Henry Smyth

  • The oblongs made of any secant from the same point, and of the outter segment of the secant are equall betweene themselves.

British Dictionary definitions for secant


  1. (of an angle) a trigonometric function that in a right-angled triangle is the ratio of the length of the hypotenuse to that of the adjacent side; the reciprocal of cosineAbbreviation: sec
  2. a line that intersects a curve
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Derived Formssecantly, adverb

Word Origin for secant

C16: from Latin secāre to cut
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for secant


1590s, from Latin secantem (nominative secans) "a cutting," present participle of secare "to cut" (see section (n.)). First used by Danish mathematician Thomas Fincke in "Geometria Rotundi" (1583).

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Online Etymology Dictionary, © 2010 Douglas Harper

secant in Science


  1. A straight line or ray that intersects a curve, especially a circle, at two or more points.
  2. The ratio of the length of the hypotenuse in a right triangle to the side adjacent to an acute angle. The secant is the inverse of the cosine.
  3. The reciprocal of the abscissa of the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.
  4. A function of a number x, equal to the secant of an angle whose measure in radians is equal to x.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.