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

This simultaneous, contrasting discourse highlights a deep bifurcation in the AI industry regarding safety, regulation, and the future trajectory of superintelligence, with competitive interests underlying the philosophical debate. — Anisha Sircar, Forbes.com, 30 July 2026

Meanwhile, guidance engineers calculated the exact trajectory the Electron rocket would have to fly to inject the Puma satellite into an orbit near True Anomaly’s Jackal satellite. — Stephen Clark, ArsTechnica, 30 July 2026

Slowinski, who has a $549 price target on the stock, wrote in a note on Thursday that the quarter showed a point of progress in the will-they-won’t-they narrative of Microsoft’s revenue trajectory versus its capital expenditures. — Amanda Gerut, Fortune, 30 July 2026

SpaceX launched its Starship vehicle on July 24, sending the 408-foot-tall (124-meter) Starship Version 3 (V3) rocket on a suborbital trajectory that saw the rocket's upper stage make its softest splashdown yet. — Brett Tingley, Space.com, 29 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