An Etymological Dictionary of Astronomy and Astrophysics

The fall of matter toward the center of a region of gravitational influence.

Etymology (EN): Infall, from → in- + → fall.

Etymology (PE): Darun-oft, from darun- “in, into; within” (Mid.Pers. andarôn
“inside,” from andar, → inter-, + rôn “side, direction;” Av. ravan- “(course of a) river”)

• oft, → fall.