An Etymological Dictionary of Astronomy and Astrophysics

The figure formed by two lines extending from a common point; the figure formed by two intersecting planes (dihedral angle).

Etymology (EN): L. angulum (nominative angulus) “corner,” a dim. form from PIE *ang-/*ank- “to bend;” cf. Skt. ankah “hook, bent,” Gk. angkon “elbow,” angkura “anchor,” Lith. anka “loop,” O.E. ancleo “ankle,” O.H.G. ango “hook,” Av. ank- “curved, crooked,” Av. angušta- “toe,” Mod.Pers. angošt, angol, angul “finger”.

Etymology (PE): Zâviyé from Ar. zâwiyat “corner, angle”.
Gušé “corner, angle,” Mid.Pers. gošak “corner.”
Konj, “angle, corner,” → diagonal.