tra·​jec·​to·​ry | \ trə-ˈjek-t(ə-)rē How to pronounce trajectory (audio) \
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

So, the biggest difference was getting a window into that, and then that really set us on a trajectory of really looking at ourselves, and set us on a healing path. Dalton Ross,, "Inside the most radical reality show transformation ever: The redemption of Colin and Christie," 19 June 2019 As the country’s growth slows and its demographic picture gets bleaker, interest rates are likely to continue on the steady downward trajectory seen in the U.S., Europe, and most notably Japan over the past three decades, boosting bond prices. Mike Bird, WSJ, "The One Chinese Asset You Should Own," 17 June 2019 One that set many clients on an upward trajectory in life. Rachel Dissell,, "Legal Aid ‘securing stability’ for low-income clients, report shows," 16 June 2019 The well liked 23-year-old with the big forehand and varied repertoire has been on an upward trajectory since and will rise six spots to No. 2 in the world behind another young star, 21-year-old Naomi Osaka, when Monday's new rankings are released. Ravi Ubha, CNN, "Ashleigh Barty beats Marketa Vondrousova to win French Open," 8 June 2019 Their universes go their separate ways, launched on a trajectory of continual unraveling. Quanta Magazine, "Why the Many-Worlds Interpretation Has Many Problems," 18 Oct. 2018 Rounds of distillery expansions and start-ups have put the sector on a trajectory toward higher production, but an industry leader warned trade disputes in key overseas markets remain a threat to the good times for bourbon producers. Bruce Schreiner, Fox News, "Kentucky bourbon inventory at highest level since 1972," 27 Sep. 2018 Even our brain size fits the pattern: While the human brain grew steadily over the last two million years, that trajectory took a sudden turn about 30,000 years ago, when brains started to become smaller. Richard Wrangham, WSJ, "Humans: The Domesticated Primates," 10 Jan. 2019 That news trajectory is in sharp relief right now in North Carolina, where Hurricane Florence made landfall to much fanfare more than a week ago. Ezra Dyer, Popular Mechanics, "I Drove a Pickup Full of Supplies to a Town Flooded by Florence, and Here Is What I Saw," 25 Sep. 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

24 Jun 2019

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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