A trajectory or flight path was the path that an object with mass in motion followed through space as a function of time.
In 2154, Hernandez had informed Jonathan Archer that they were matching speed and trajectory as requested. (ENT: "Divergence")
In 2381, the USS Voyager was briefly hijacked by an assimilated animatronic model, Doctor Chaotica, The Clown, and Michael Sullivan, all of whom attempted to redirect Voyager's trajectory to Cube 858779. However, their plan was ultimately foiled by Ensigns Sam Rutherford and Brad Boimler. (LD: "Twovix")