trajectory
truh-JEK-tuh-ree
/trəˈdʒɛktəri/
The curved path that an object follows after it has been thrown, launched, or shot into the air or space.
Implies a predictable, mathematically calculable path governed by gravity and other external forces.
The story behind the word. From the Latin 'traicere', meaning 'to throw across'. It combines 'trans-' (across) and 'jacere' (to throw). It is a direct sibling of 'reject' (throw back), 'project' (throw forward), and 'eject' (throw out).
Word relationships
- path: Path is a general term for any route, while trajectory specifically implies a curved, ballistic, or calculated flight path.
- course: Course often implies active steering or navigation, whereas trajectory emphasizes the physics-based arc of a projectile.
Commonly confused with
- orbit: An orbit is a continuous, repeating closed loop around a celestial body, whereas a trajectory can be a one-way arc or path.
Word family
- trajectories (noun): Plural form of trajectory.
Collocations
- flight trajectory
- orbital trajectory
- downward trajectory
Example sentences
- "A slight error in the initial launch angle can throw the spacecraft off its planned trajectory to Mars by millions of miles." Space flight calculation
- "Her career trajectory shifted dramatically after she transitioned from corporate law to aerospace engineering." Metaphorical career path
Memory hook
Think of a 'project' being 'thrown' across a 'track'—that's its trajectory. Thrown across.
When not to use
Do not use for highly erratic, unpredictable paths that cannot be modeled (e.g., a fly buzzing around a room).
Fun facts
- Spacecraft traveling to outer planets use 'gravitational slingshots' to alter their trajectory and gain speed without burning extra fuel.
Explore more words
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.