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

While the company had a strong debut, with shares soaring 19% on their first day of trading to as high as $193, it’s largely been on a downward trajectory since then. — Steve Kopack, NBC news, 16 July 2026

If the mission lasts beyond 2029, New Horizons may follow in the historic steps of the Voyager probes as the spacecraft’s current trajectory will take it outside the heliosphere and into interstellar space. — Ashley Strickland, CNN Money, 16 July 2026

With her exit, Fineman follows the standard trajectory for successful SNL cast members who leave after the end of their initial seven-year contract. — Nellie Andreeva, Deadline, 16 July 2026

Meanwhile, Starship would continue on its suborbital trajectory, deploying a payload of 20 Starlink V3 satellites once in space. — Lee Billings & Claire Cameron, Scientific American, 16 July 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