An Etymological Dictionary of Astronomy and Astrophysics

In Ptolemy’s geocentric model, the circle around the Earth in which the center of the → epicycle of a body was thought to move.

Etymology (EN): Deferent, from L. deferent-, pr.p. of deferre “to carry from or down, transfer” from → de- + ferre “to carry, bear,” from PIE *bher- “to bear, to carry, to take” (cf. O.Pers./Av. bar- “to bear, carry,” barəθre “to bear” (infinitive), Mod.Pers. bordan, bar- “to carry,”
Skt. bharati “he carries,” Gk. pherein “to carry”).

Etymology (PE): Falak-e hâmel, from Ar. falak “heaven; orbit, sphere” + hamil “carrier.”