The curved path that an object makes in space, or that a thrown object follows as it rises and falls to earth.
Considering the likely range, trajectory, and accuracy of a bullet fired from a cheap handgun at 150 yards, the murder seemed incredible.
Formed with part of the prefix trans-, "across," trajectory means a "hurling across." By calculating the effect of gravitational 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. Though the word is most used in physics and engineering, we can also say, for example, that the trajectory of a whole life may be set in a person's youth, or that a historian has described the long trajectory of the French empire in a new book.