[tra.jec.to.ry] n, pl -ries [NL trajectoria, fr. fem. of trajectorius of passing, fr. L traicere to cause to cross, cross, fr. trans-, tra- trans- + jacere to throw--more at jet] (1696) 1: the curve that a body (as a planet or comet in its orbit or a rocket) describes in space
2: a path, progression, or line of development resembling a physical trajectory