trajectory

Concise Oxford English Dictionary © 2008 Oxford University Press:
trajectory /trəˈdʒɛkt(ə)ri, ˈtradʒɪkt(ə)ri/

▶noun (pl. trajectories)

• 1 the path described by a projectile flying or an object moving under the action of given forces.

• 2 Geometry a curve or surface cutting a family of curves or surfaces at a constant angle.

– origin C17: from mod. L. trajectoria (fem.), from L. traject-, traicere ‘throw across’.