An Etymological Dictionary of Astronomy and Astrophysics

A combining form meaning “false, erroneous, pretended, unreal,” used in the formation of compound words (pseudonym, pseudoclassic, pseudointellectual). In scientific use, denoting close or deceptive resemblance to the following element (pseudogene, pseudobulb, pseudocarp).
→ pseudo-disk, → pseudo-Euclidean space, → pseudo-nucleus, → pseudo-Riemannian space, → pseudoscience.

Etymology (EN): From Gk. pseudo-, combining form of pseudes “false,” or pseudos “falsehood,” both from pseudein “to lie, cheat, falsify.”

Etymology (PE): Doruž-, from Mid.Pers. druž “false, untrue, deceptive” (Mod.Pers. doruq “lie”), drôzitan, druxtan “to lie;” O.Pers. drauga- “lie;” Av. drug- “to lie,” družaiti “he lies, cheats;” cf. Skt. druhyati “he lies,” drôha-, drôgha- “insult, injury,” druh- “damage; ghost;”
O.H.G. triogan “to deceive;” Ger. trügen “to deceive;” E. dream; PIE base *dhrugh- “to deceive, harm.”