trajectory

[ truh-jek-tuh-ree ]

noun

, plural tra·jec·to·ries.

1. the curve described by a projectile, rocket, or the like in its flight.
2. Geometry. a curve or surface that cuts all the curves or surfaces of a given system at a constant angle.

trajectory

/ -trɪ; trəˈdʒɛktaɪl; trəˈdʒɛktərɪ /

noun

1. 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
2. geometry a curve that cuts a family of curves or surfaces at a constant angle

trajectory

/ trə-jĕk′tə-rē /

1. Physics.
   The line or curve described by an object moving through space.
2. 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.

Derived Forms

• trajectile, adjective

Other Words From

• tra·jec·tile [tr, uh, -, jek, -til, -tahyl], adjective
• tra·jec·tion [tr, uh, -, jek, -sh, uh, n], noun

Word History and Origins

Origin of trajectory¹

First recorded in 1660–70; from New Latin trājectōria, noun use of feminine of Medieval Latin trājectōrius “casting over”; equivalent to traject + -tory ¹

Example Sentences

Demand is expected to continue its downward trajectory in the coming years as California increases its utilization of renewable energy sources.

From Los Angeles Times

“Making changes that impact students’ educational trajectories must always be done with transparency and care,” Schmerelson said in a statement Monday.

From Los Angeles Times

He believed that as a result of the policies put in place by President Biden and with the support of states and cities, US emissions would continue their downward trajectory, albeit at a slower pace.

From BBC

The one-term president made it clear he was unhappy with the results but hoped the country would continue the upward trajectory his administration set in motion.

From Salon

Whether a different candidate might have produced a different result is unknowable, but as I’ve already suggested, this outcome was likely overdetermined by the Democratic Party’s trajectory of self-destruction.

From Salon

Related Words

• curve
• orbit
• path

More About Trajectory

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.

Where does trajectory come from?

The first records of the word trajectory come from the 1660s. It comes from the Latin trājectōrius, meaning “casting over,” from the verb trāicere, “to cast” or “to throw over or across.” The first part of the word is equivalent to trans-, meaning “across,” and the root jec comes from the Latin verb jacere, meaning “to throw” (the same root forms the basis of motion-related words like projectile, eject, and many others).

Thanks to gravity, what goes up must come down. The path that something follows as it takes the journey up and then down again is its trajectory. When gravity is in play, objects that are thrown or propelled in some way follow a trajectory in the shape of what’s technically known as a parabola, which is basically a kind of curve. The word trajectory is commonly applied to the path of things that travel in this way, but it can be used more generally to simply refer to the route of something from one place to another, such as the trajectory of a storm. It can also be used in a more figurative way, as in career trajectory—meaning the path that one’s career has taken.

Did you know ... ?

What are some other forms related to trajectory?

• trajectories (plural)
• trajectile (adjective)
• trajection (noun)

What are some synonyms for trajectory?

• course
• path
• route
• track

What are some words that share a root or word element with trajectory?

• transit
• projectile
• eject

What are some words that often get used in discussing trajectory?

 

• curve
• flight
• rocket
• missile
• bullet
• storm
• parabola
• geometry

How is trajectory used in real life?

The word trajectory is commonly used to refer to the path of projectiles like rockets, but it can be used in many different contexts.

I’m gonna hire an architect and build a Wrigley Field fountain that has water shooting in the exact trajectory of javier Baez’s home runs. https://t.co/YX2sfr4iwV

— Basia Marotta (@BasiaMarotta) August 3, 2018

The rocket has separated from the first stage and is being boosted to orbit by the Centaur second stage. @NASAPersevere is now preparing for a second burn that will put it on a trajectory towards Mars. #CountdownToMars pic.twitter.com/MBRqcxMTdw

— NASA (@NASA) July 30, 2020

The Head of Forecasting at Met Éireann has said it is impossible to predict how Hurricane Lorenzo will affect Ireland, but the storm's trajectory should become clearer over the next 48 hours https://t.co/IgqadWUw7p

— RTÉ News (@rtenews) September 30, 2019

 

 

Try using trajectory!

Which of the following words is not a synonym of trajectory?

A. path
B. route
C. point
D. track