trajectory

Where does the word "trajectory" come from? It comes from Latin traicere, passing through New Latin before entering English (1690s).

Trajectory’s story begins in Latin: traicere meant “to throw across.” To throw across, from trans- (across) and iacere (to throw), with irregular past participle trajectus. By 1600s, the word had taken hold in New Latin as trajectoria. Formed for the path of a body moving through space. It reached English by 1690s as trajectory. Settled as the English word for the curved path an object follows. Today, trajectory means the path followed by an object moving through space, or a general course of development.

1. Stage 1 · Latin · ancient traicere "to throw across", to throw across, from trans- (across) and iacere (to throw), with irregular past participle trajectus.
2. Stage 2 · New Latin · 1600s trajectoria "the path of a moving body", formed for the path of a body moving through space.
3. Stage 3 · English · 1690s trajectory "the curved path an object follows through space", settled as the English word for the curved path an object follows.