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

2

: a path, progression, or line of development resembling a physical trajectory

an upward career 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 premier class of motorcycle racing could follow a similar growth trajectory that F1 witnessed after Liberty took over the sport in 2017, especially in the American market. —Saajan Jogia, MSNBC Newsweek, 14 Oct. 2025

The vehicle also deployed some payloads — eight dummy versions of SpaceX's Starlink satellites, which were released on the same suborbital trajectory as that of Ship. —Mike Wall, Space.com, 14 Oct. 2025

Figure argues—convincingly—that its robots are on this trajectory. —Billy Perrigo, Time, 14 Oct. 2025

This emptying-out trajectory may be familiar to anyone who's read accounts of contemplative mystical experiences. —Jim Higgins, jsonline.com, 13 Oct. 2025

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