trajectory

noun

tra·​jec·​to·​ry trə-ˈjek-t(ə-)rē 

plural trajectories

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

As investors sift through the jobs data in the week ahead, the goal is to gain at least some additional clarity on the economy’s trajectory and the Fed’s next moves. —Zev Fima, CNBC, 29 Mar. 2026

To be clear, the astronauts aboard Orion for Artemis 2 won't actually enter orbit around the moon, but will instead slingshot around the lunar far side in a figure-eight trajectory that puts the spacecraft on a direct course back to Earth. —Josh Dinner, Space.com, 29 Mar. 2026

Massachusetts shouldn’t accept this downward trajectory. —Editorial, Boston Herald, 29 Mar. 2026

Like Apollo 13, Artemis II will take advantage of the moon and Earth’s gravity, making a figure eight after whipping around the moon to head home in what’s known as a free-return trajectory requiring little if any fuel. —Marcia Dunn, Chicago Tribune, 29 Mar. 2026

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

Rhymes for trajectory

• directory
• refectory
• nectary
• rectory
• subdirectory

Kids Definition

trajectory

noun

tra·​jec·​to·​ry trə-ˈjek-t(ə-)rē 

plural trajectories

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