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

The trajectory of the Trojans’ season has turned downward since. — Ryan Kartje, Los Angeles Times, 28 Oct. 2026

The pairing isn’t quite as explosive as Hawkins and Cam Cook were for West Virginia, but both players can change the trajectories of games with their speed. — Steven Johnson, Fort Worth Star-Telegram, 28 Oct. 2026

Martinez lost the race to Democrat Lawton Chiles, but DeFoor’s career continued on an upward trajectory. — David Goodhue, Miami Herald, 28 Oct. 2026

Even if Netanyahu loses, new leadership is unlikely to radically change Israel’s trajectory on issues important to the US. — Lauren Morganbesser, semafor.com, 27 Oct. 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