From Modern Latin trajectorium, from trajectorius (“of or pertaining to throwing across”), from Latin traiectus (“thrown over or across”), past participle of traicere, from Latin trans (“across, beyond”) (see trans-) + icere, combining form of iacere (“to throw”) (from PIE root *ye- "to throw, impel"). Middle French and Middle English had trajectorie as "end of a funnel", from Latin traiectorium.
trajectory (plural trajectories)
- (astronomy, space science) The path of a body as it travels through space.
- (cybernetics) The ordered set of intermediate states assumed by a dynamical system as a result of time evolution.
- Metaphorically, a course of development, such as that of a war or career.
2013 March 1, Harold J. Morowitz, “The Smallest Cell”, in American Scientist, volume 101, number 2, page 83:
- It is likely that the long evolutionary trajectory of Mycoplasma went from a reductive autotroph to oxidative heterotroph to a cell-wall–defective degenerate parasite. This evolutionary trajectory assumes the simplicity to complexity route of biogenesis, a point of view that is not universally accepted.
- (astronomy, space): flyby trajectory
- (cybernetics): run