Try Our Apps


Avoid these words. Seriously.


[truh-jek-tuh-ree] /trəˈdʒɛk tə ri/
noun, plural trajectories.
the curve described by a projectile, rocket, or the like in its flight.
Geometry. a curve or surface that cuts all the curves or surfaces of a given system at a constant angle.
Origin of trajectory
1660-70; < New Latin trājectōria, noun use of feminine of Medieval Latin trājectōrius cast-ing over. See traject, -tory1
Related forms
[truh-jek-til, -tahyl] /trəˈdʒɛk tɪl, -taɪl/ (Show IPA),
[truh-jek-shuh n] /trəˈdʒɛk ʃən/ (Show IPA),
noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for trajectory
Contemporary Examples
Historical Examples
  • It was just at the second when it reached the top of its trajectory and started to fall.

    High Adventure James Norman Hall
  • What we retain of the movement of the mobile T are positions taken on its trajectory.

    Creative Evolution Henri Bergson
  • But the rest of his mind tried to imagine such a trajectory.

    Talents, Incorporated William Fitzgerald Jenkins
  • Some pitched into the hospital forty yards away, their trajectory just above us.

    The Secrets of a Kuttite Edward O. Mousley
  • The greater the velocity, the flatter the trajectory becomes.

    Gunshot Roentgenograms Clyde S. Ford
British Dictionary definitions for trajectory


/trəˈdʒɛktərɪ; -trɪ/
noun (pl) -ries
the path described by an object moving in air or space under the influence of such forces as thrust, wind resistance, and gravity, esp the curved path of a projectile
(geometry) a curve that cuts a family of curves or surfaces at a constant angle
Derived Forms
trajectile (trəˈdʒɛktaɪl) adjective
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
Cite This Source
Word Origin and History for trajectory

1690s, from Modern Latin trajectoria, from fem. of trajectorius "of or pertaining to throwing across," from Latin traiectus "thrown over or across," past participle of traicere "throw across," from Latin trans- "across" (see trans-) + icere, combining form of iacere "to throw" (see jet (v.)). Used in Late Latin and Middle English to mean "a funnel."

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
trajectory in Science
  1. Physics The line or curve described by an object moving through space.

  2. Mathematics A curve or surface that passes through a given set of points or intersects a given series of curves or surfaces at a constant angle.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Nearby words for trajectory

Word Value for trajectory

Scrabble Words With Friends