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 Prediction Ohio State 68, Michigan 67: Ohio State, in many ways, has experienced a similar trajectory as Michigan: Fast out of the gates, followed by a slump in conference play. Orion Sang, Detroit Free Press, "Michigan basketball vs. Ohio State: Scouting report, prediction," 4 Feb. 2020 The only thing that will get Trump out of the Oval Office, and perhaps alter the trajectory of the Republican Party, is a comprehensive defeat in November. John Cassidy, The New Yorker, "Trump’s Inevitable Acquittal and the Threat to American Democracy," 1 Feb. 2020 The findings, released jointly by NASA and the National Oceanic and Atmospheric Administration (NOAA), detail a troubling trajectory: 2019 was the second-hottest year on record, trailing only 2016. Washington Post, "2019 capped off the world’s hottest decade in recorded history," 15 Jan. 2020 But Anthony’s late-career trajectory, from franchise cornerstone with the Denver Nuggets and New York Knicks to near-pariah, may speak to something else. Robert O'connell, The Atlantic, "Carmelo Anthony’s Melancholy NBA Return," 22 Nov. 2019 Lager remains the most popular beer style in the U.S., but the macro-lagers — the Coors and Buds — are on a downward trajectory, shrinking 2% by volume in 2018, according to industry analyst IWSR. Esther Mobley,, "The hot new thing in craft beer? Good old-fashioned lager," 31 Jan. 2020 And the most severe trajectory, which presumes that emissions will grow throughout this century, could result in as much as 5 degrees C — that's about 9 degrees Fahrenheit — of additional global warming by the year 2100. Chelsea Harvey, Scientific American, "The Worst Climate Scenarios May No Longer Be the Most Likely," 30 Jan. 2020 Thrust, trajectory, speed and flight-control features were working as expected, according to U.S. aviation officials. Georgi Kantchev, WSJ, "Before Doomed Flight From Tehran, Anxiety and a Final Kiss," 24 Jan. 2020 In a nutshell, they are controlled-expansion bullets for your shotgun, designed to deliver high muzzle velocities and flat trajectories, yet open up at comparatively low impact velocities to flatten game. Richard Mann, Field & Stream, "Best New Hunting, Long-Range, and Handgun Ammo of the 2020 SHOT Show," 22 Jan. 2020

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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Time Traveler for trajectory

Time Traveler

The first known use of trajectory was in 1696

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Statistics for trajectory

Last Updated

18 Feb 2020

Cite this Entry

“Trajectory.” Dictionary, Merriam-Webster, Accessed 25 Feb. 2020.

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How to pronounce trajectory (audio)

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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