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

Lee’s paintings since the later ’90s develop this trajectory. — Barry Schwabsky, Artforum, 1 Oct. 2026

Without intervention, their trajectory leads to a profoundly medicalized adulthood. — Babak J. Orandi, STAT, 1 Oct. 2026

Ultrasensitive, longer-range quantum RF sensing devices use changes in electron trajectory to extract more information out of the RF environment than conventional antennas. — Prabhat Ranjan Mishra, Interesting Engineering, 30 Sep. 2026

The trajectory of income growth indicates that the current pace of consumer spending is likely to slow but still remain fairly solid, said Gus Faucher, senior vice president and chief economist at The PNC Financial Services Group. — Alicia Wallace, CNN Money, 30 Sep. 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