the branch of mathematics that deals with the relations between the sides and angles of plane or spherical triangles, and the calculations based on them.

Origin of trigonometry

1605–15; < New Latin trigōnometria; see trigon, -o-, -metry
Related formstrig·o·no·met·ric [trig-uh-nuh-me-trik] /ˌtrɪg ə nəˈmɛ trɪk/, trig·o·no·met·ri·cal, adjectivetrig·o·no·met·ri·cal·ly, adverbnon·trig·o·no·met·ric, adjectivenon·trig·o·no·met·ri·cal, adjectivenon·trig·o·no·met·ri·cal·ly, adverbun·trig·o·no·met·ric, adjectiveun·trig·o·no·met·ri·cal, adjectiveun·trig·o·no·met·ri·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for trigonometry

Historical Examples of trigonometry

  • It signifies an enormous number of things, from pot-hooks to trigonometry.

    The Curse of Education

    Harold E. Gorst

  • This is not because the details of trigonometry are all needed in physics.

    College Teaching

    Paul Klapper

  • I worked off a year's trigonometry that summer, and began Virgil alone.

    My Antonia

    Willa Cather

  • They found them deficient in trigonometry and canned them off the team.

    At Good Old Siwash

    George Fitch

  • I never saw him but during a fortnight, when I took it into my head to do trigonometry.

    Rowlandson's Oxford

    A. Hamilton Gibbs

British Dictionary definitions for trigonometry



the branch of mathematics concerned with the properties of trigonometric functions and their application to the determination of the angles and sides of triangles. Used in surveying, navigation, etcAbbreviation: trig
Derived Formstrigonometric (ˌtrɪɡənəˈmɛtrɪk) or trigonometrical, adjectivetrigonometrically, adverb

Word Origin for trigonometry

C17: from New Latin trigōnometria from Greek trigōnon triangle
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 trigonometry

"branch of mathematics that deals with relations between sides and angles of triangles," 1610s, from Modern Latin trigonometria (Barthelemi Pitiscus, 1595), from Greek trigonon "triangle" (from tri- "three," see tri-, + gonia "angle," see knee (n.)) + metron "a measure" (see meter (n.2)).

Online Etymology Dictionary, © 2010 Douglas Harper

trigonometry in Science



The study of the properties and uses of trigonometric functions.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.