An Etymological Dictionary of Astronomy and Astrophysics

The apparent → shift of a nearby object’s → position in relation to more distant ones when the nearby object is observed from different → viewing angles. See also → stellar parallax.

Etymology (EN): From M.Fr. parallaxe, from Gk. parallaxis “change, alteration,” from parallassein “to alter, make things alternate,” from → para- “beside” + allassein “to change,” from allos “other;” → alias.

Etymology (PE): Didgašt, literally “view change,” from did “sight, view; eye,” from didan “to see” (Mid.Pers. ditan “to see, regard, catch sight of, contemplate, experience;” O.Pers. dī- “to see;” Av. dā(y)- “to see,” didāti “sees;” cf.
Skt. dhī- “to perceive, think, ponder; thought, reflection, meditation,” dādhye; Gk. dedorka “have seen”) + gašt “change, alteration,” past stem of gaštan, gardidan “to turn, to change” (Mid.Pers. vartitan; Av. varət- “to turn, revolve;” Skt. vrt- “to turn, roll,” vartate “it turns round, rolls;” L. vertere “to turn;” O.H.G. werden “to become;” PIE base *wer- “to turn, bend”).