An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A curved path followed by an unpowered object that is being acted upon only by gravitational forces and the friction of the medium through which it moves.

→ ballistic; → trajectory.

Math.: A curve which intersects every member of a given one-parameter family of curves at one and the same angle.

→ isogonal; → trajectory.

Math.: An → isogonal trajectory where the family of curves are cut at right angles.

→ orthogonal; → trajectory.

Physics: The line or curve described by an object moving through space.
Math.: A curve or surface that cuts all of a given family of curves or surfaces at the same angle.

From Mod.L. trajectoria, from feminine of trajectorius "of or pertaining to throwing across," from L. trajectus "thrown over or across," p.p. of trajicere "throw across," from L. → trans- "across" + icere, combining form of jacere "to throw," → eject.

Tarâyešâné, from tarâ- "across," → trans-, + -y- epenthetic + ešân, present stem of ešândan, → eject, + relation suffix -é.