tra·jec·to·ry | \trə-ˈjek-t(ə-)rē \
plural trajectories

Definition of trajectory 

1 : the curve that a body (such as a planet or comet in its orbit or a rocket) describes in space

2 : a path, progression, or line of development resembling a physical trajectory an upward career trajectory

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Did You Know?

Formed with part of the prefix trans-, "across", trajectory means a "hurling across". By calculating the effect of gravity and other forces, the trajectory of an object launched into space at a known speed can be computed precisely. Missiles stand a chance of hitting their target only if their trajectory has been plotted accurately. The word is used most often in physics and engineering, but not always; we can also say, for example, that the trajectory of a whole life may be set in a person's youth, or that a new book traces the long trajectory of the French empire.

Examples of trajectory in a Sentence

the trajectory of the missile

Recent Examples on the Web

More refugees of varied wartime trajectories flooded the monastery as Allied forces emptied out camps, Grossman says. Emanuella Grinberg, Smithsonian, "When a Bavarian Monastery Provided a Home to Jewish Refugees," 11 July 2018 Müller and his team found hints of a different developmental trajectory by comparing children of different ages. Rachel Zamzow, Scientific American, "Brains of Children with Autism Show Unusual Folding Patterns," 9 July 2018 That striking trajectory emerges from previously unreleased data Pew provided to me from its survey published in late May comparing attitudes in urban, suburban and small-town America. Ronald Brownstein, CNN, "Republicans and Democrats increasingly really do occupy different worlds," 12 June 2018 Then in October, New Horizons will fire its thrusters and perform the first of seven maneuvers to change is trajectory. Loren Grush, The Verge, "NASA’s New Horizons probe woke up today to prep for its next deep space flyby," 5 June 2018 That seemed to be the trajectory of an incident in Memphis earlier this month, but then there was an unusual twist. Doug Criss, CNN, "A white woman sees a black man inspecting a house and calls the cops. But there's a twist to this incident," 16 May 2018 Carlos Carrasco, Indians Carrasco’s first three starts of the year were a perfect upward trajectory. Michael Beller,, "The Table Setter: Pleading for Mercy from the Winter, and Previewing the Season's Third Week," 16 Apr. 2018 Then again, that was Andrew Miller’s trajectory as well. Jorge L. Ortiz, USA TODAY, "One of MLB's most valuable pitchers, Diamondbacks' Archie Bradley not worried about paycheck," 13 Apr. 2018 And however justified, that has indeed been the trajectory of Trump's line of defense — with some handy assists from the Justice Department and House Republicans. Aaron Blake, Washington Post, "Trump lawyer’s call for end to Russia probe is all about the investigation’s aftermath — or firing Mueller," 17 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'trajectory.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of trajectory

1696, in the meaning defined at sense 1

History and Etymology for trajectory

New Latin trajectoria, from feminine of trajectorius of passing, from Latin traicere to cause to cross, cross, from trans-, tra- trans- + jacere to throw — more at jet

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Statistics for trajectory

Last Updated

14 Oct 2018

Look-up Popularity

Time Traveler for trajectory

The first known use of trajectory was in 1696

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English Language Learners Definition of trajectory

: the curved path along which something (such as a rocket) moves through the air or through space

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lying above or upon

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