trajectory
Americannoun
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trajectories
plural
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the curve described by a projectile, rocket, or the like in its flight.
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Geometry. a curve or surface that cuts all the curves or surfaces of a given system at a constant angle.
noun
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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
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geometry a curve that cuts a family of curves or surfaces at a constant angle
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Physics The line or curve described by an object moving through space.
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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.
Usage
What does trajectory mean? The trajectory of an object is the path it follows once in flight or in motion. The word is especially used in the context of the path of projectiles like rockets, but it can be used in many different contexts. The trajectory of a golf ball is the curved path it follows in the air after being hit by a golf club. The trajectory of an asteroid is the path it follows in space. The potential trajectory of a storm is the route that it may travel. In geometry, trajectory is used in a more specific way to refer to a curve that intersects through a series of points at the same angle. Example: Try to determine the trajectory of the ball as it flies through the air so you can position yourself to catch it.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of trajectory
First recorded in 1660–70; from New Latin trājectōria, noun use of feminine of Medieval Latin trājectōrius “casting over”; equivalent to traject + -tory 1
Explanation
If you stay on your current trajectory of constant shopping, dining out, and yacht rentals, you'll end up broke. A trajectory is the path of an object through space, or the path of life that a person chooses. Trajectory comes from the Latin trajectoria, which means "throw across." The prefix tra- is short for trans-, which means "across" (think transport and transit) and the ject comes from jacere, which means "throw" and is also the root of the word jet. If you wanted to describe the path of a jet through the sky, you could refer to the jet's trajectory.
Vocabulary lists containing trajectory
The Alchemist
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Freak the Mighty
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Into the Wild
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
One decision changed their palates—and the trajectory of some New York City restaurants.
From The Wall Street Journal ● Aug. 16, 2026
"The longitudinal exploration of cardiovascular health throughout life, rather than assessing it at a single time point, could also provide further insight into the trajectory phenotypes contributing to cognitive decline by ethnicity," Vazquez said.
From Science Daily ● Aug. 16, 2026
Manus' trajectory shifted abruptly in mid-2025, when the firm laid off dozens of staff in Beijing and Wuhan and relocated core personnel to Singapore.
From Barron's ● Aug. 11, 2026
“We have not seen an El Niño event already on the trajectory that this one is on.”
From Los Angeles Times ● Aug. 10, 2026
As Nina tracked the group with her eyes, Inej moved over the roof, following their trajectory.
From "Six of Crows" by Leigh Bardugo
They remain on very different trajectories, with William's life heading remorselessly to the point where he will take to the throne.
From BBC ● Jul. 4, 2026
In some ways, it’s a journey that mirrors the actors’ own trajectories.
From Los Angeles Times ● Jun. 26, 2026
As the typically busy spring housing season heads toward the summer, trajectories vary dramatically by location.
From Barron's ● May 5, 2026
After training on 3D particle trajectories, the AI successfully captured complex interactions, including asymmetrical forces between particles.
From Science Daily ● Apr. 23, 2026
All performed flawlessly, flying nice elliptical trajectories downrange to impact on the slack.
From "October Sky" by Homer Hickam
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
