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

Three AMAs in a single night, three months later, is the next significant marker on a trajectory that is clearly moving forward. —Hannah Abraham, Forbes.com, 26 May 2026

As part of a new cohort of directors that came up on YouTube before making their feature debuts, Parsons hasn’t noticed any stigma around that trajectory in his own journey to the big screen. —Glenn Garner, Deadline, 25 May 2026

Nothing Starship accomplished on Flight 12 was particularly groundbreaking for SpaceX; the mission goals and trajectories were broadly similar to those of the previous few test missions. —Josh Dinner, Space.com, 23 May 2026

All 12 of SpaceX’s Starship test flights to date have flown on suborbital trajectories. —Stephen Clark, ArsTechnica, 23 May 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