Old English wryhta, wrihta (Northumbrian wyrchta, Kentish werhta) "worker," variant of earlier wyhrta "maker," from wyrcan "to work" (see work (v.)). Now usually in combinations (wheelwright, playwright, etc.) or as a surname. A common West Germanic word; cognate with Old Saxon wurhito, Old Frisian wrichta, Old High German wurhto.
Smith was the general term for a worker in metals, and wright for one who worked in wood, and other materials. Hence, in the later English period, smith (which, in Anglo-Saxon, when used without any characteristic addition, was understood as applying more particularly to the worker in iron,) became the particular name of a blacksmith, and wright of a carpenter, as it is still in Scotland. [Thomas Wright, "Anglo-Saxon and Old English Vocabularies," 1884]
*terə-, Proto-Indo-European root meaning "to rub, turn," with derivatives referring to twisting, also to boring, drilling, piercing; and to the rubbing of cereal grain to remove the husks, and thus to threshing.
It forms all or part of: atresia; attorn; attorney; attrition; contour; contrite; detour; detriment; diatribe; drill (v.) "bore a hole;" lithotripsy; return; septentrion; thrash; thread; thresh; throw; threshold; trauma; trepan; tribadism; tribology; tribulation; trite; triticale; triturate; trout; trypsin; tryptophan; turn.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit turah "wounded, hurt;" Greek teirein "to rub, rub away;" Latin terere "to rub, thresh, grind, wear away," tornus "turning lathe;" Old Church Slavonic tiro "to rub;" Lithuanian trinu, trinti "to rub," Old Irish tarathar "borer," Welsh taraw "to strike."