"morally correct," O.E. riht "just, good, fair, proper, fitting, straight," from P.Gmc. *rekhtaz (cf. O.H.G. reht, Ger. recht, O.N. rettr, Goth. raihts), from PIE base *reg- "move in a straight line," also "to rule, to lead straight, to put right" (see regal; cf. Gk. orektos "stretched out, upright;" L. rectus "straight, right;" O.Pers. rasta- "straight, right," aršta- "rectitude;" O.Ir. recht "law;" Welsh rhaith, Breton reiz "just, righteous, wise"). Cf. slang straight "honest, morally upright," and L. rectus "right," lit. "straight," Lith. teisus "right, true," lit. "straight." Gk. dikaios "just" (in the moral and legal sense) is from dike "custom." The noun sense of "just claim" was in O.E. and P.Gmc. As an emphatic, meaning "you are right," it is recorded from 1588; use as a question meaning "am I not right?" is from 1961. The phrase to rights "at once, straightway" is 1663, from sense "in a proper manner" (M.E.). The sense in right whale is "justly entitled to the name." Phrase right off the bat is 1914, earlier hot from the bat (1888), probably a baseball metaphor; right stuff "best human ingredients" is from 1848, popularized by Tom Wolfe's 1979 book about the first astronauts. Right on! as an exclamation of approval first recorded 1925 in black slang, popularized mid-1960s by Black Panther movement. Right of way is attested from 1768.
"opposite of left," 1125, riht, from O.E. riht, which did not have this sense but meant "good, proper, fitting, straight" (see right (adj.1) ). The notion is of the right hand as the "correct" hand. The O.E. word for this was swiţra, lit. "stronger." "The history of words for 'right' and 'left' shows that they were used primarily with reference to the hands" [Buck]. Cf. similar sense evolution in Du. recht, Ger. recht "right (not left)," from O.H.G. reht, which meant only "straight, just." The usual PIE root (*deks(i)-) is represented by Skt. daksina-, Gk. dexios, L. dexter (cf. O.Fr. destre, Sp. diestro, etc.), Ir. dess, Welsh deheu, Goth. taihswa, Lith. desinas, O.C.S. desnu, Rus. desnoj. Other derivations on a similar pattern to Eng. right are Fr. droit, from L. directus "straight;" Lith. labas, lit. "good;" and Slavic words (Boh. pravy, Pol. prawy, Rus. pravyj) from O.C.S. pravu, lit. "straight." The political sense of "conservative" is first recorded 1794 (adj.), 1825 (n.), a translation of Fr. Droit "the Right, Conservative Party" in the Fr. National Assembly (1789; see left). Right wing in political sense is first recorded 1905. Right hand, fig. for "indispensable person" is recorded from 1528; right-hand man first attested 1665.