plural trajectories
Synonyms of trajectory
1
: the curve that a body (such as a planet or comet in its orbit or a rocket) describes in space
the trajectory of a missile
2
: a path, progression, or line of development resembling a physical trajectory
an upward career trajectory
the nation's economic trajectory

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The real uncertainty centers on his future policy trajectory. CNBC, 28 Aug. 2026 Current global policies put Earth on a trajectory to warm by about 5 degrees above preindustrial levels by the end of the century. Sibi Arasu, Los Angeles Times, 27 Aug. 2026 Then, as Pike prepares to hand over the bridge to Lieutenant Rahda (Abinaya Sivakumaran), his replacement notices a slight shift in the ship’s trajectory. Keith Phipps, Vulture, 27 Aug. 2026 The smallest robot was the most agile of the three, and the largest one was the best at maintaining its trajectory when faced with disturbances meant to throw it off course. Mack Degeurin, Popular Science, 27 Aug. 2026 See All Example Sentences for trajectory

Word History

Etymology

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

First Known Use

1696, in the meaning defined at sense 1

Time Traveler
The first known use of trajectory was in 1696

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Cite this Entry

“Trajectory.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trajectory. Accessed 1 Sep. 2026.

Kids Definition

trajectory

noun
plural trajectories
: the curve that a body (as a planet in its orbit or a rocket) travels along in space

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