The English surname, however, is literally "a dyer," attested from c. 1300, from a variant of deie "dye" (see dye (n.)) + feminine agent suffix -ster. Its immediate source is Old English degstre, from deagian "to dye." The parallel form in Middle English was deister "dyer" attested from c. 1300, from 13c. as a surname (Deyster, Dygestre).
1560s, "pertaining to or situated on the right hand," from Latin dexter "on the right hand" (source also of French dextre, Spanish diestro, Italian destro), from PIE root *deks- "right, opposite of left; south." The Latin form is with the comparative suffix -ter, thus meaning etymologically "the better direction." Middle English dester meant "right hand," and compare destrier. In heraldry, the part of the shield which is to the right when fitted on the arm, hence the side of the field to the left of the spectator.
1520s, "manual skill, skill in using the hands; physical adroitness in general," from French dexterité (16c.), from Latin dexteritatem (nominative dexteritas) "readiness, skillfulness, prosperity," from dexter "skillful," also "right (hand)," from PIE root *deks- "right, on the right hand," also "south." Compare dexter. In 16c.-18c. also "mental adroitness or skill," often in a bad sense, "cleverness in taking advantage or avoiding responsibility."
Proto-Indo-European root meaning "right, opposite left," hence "south" (from the viewpoint of one facing east).
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit daksinah "on the right hand, southern, skillful;" Avestan dashina- "on the right hand;" Greek dexios "on the right hand," also "fortunate, clever;" Latin dexter "skillful," also "right (hand);" Old Irish dess "on the right hand, southern;" Welsh deheu; Gaulish Dexsiva, name of a goddess of fortune; Gothic taihswa; Lithuanian dešinas; Old Church Slavonic desnu, Russian desnoj.
word-forming element meaning "toward or on the right-hand side," from combining form of Latin dexter (from PIE root *deks- "right, opposite of left; south").
c. 1600, "convenient, suitable" (a sense now obsolete), formed in English from Latin dexter "skillful" (from PIE root *deks- "right, opposite of left; south") + -ous. Sense of "deft or nimble with the hands, quick and precise in action" is from 1630s. Meaning "mentally skillful, clever" is from 1620s. Related: Dexterously; dexterousness.
1640s, "right as opposed to left," from Medieval Latin dexteralis "on the right," from Latin dexter "right, opposite of left," from PIE root *deks-. From 1871 as "right-handed." By 1818 in reference to univalve shells, "having the aperture on the right side when held upright in front of the observer with the apex upward." Related: Dextrally; dextrality.
c. 1400, sautour, an ordinary that resembles a St. Andrew's Cross on a shield or flag, consisting of a bend dexter and a bend sinister crossing each other, from Old French sautoir, sautour, literally "stirrup," and directly from Medieval Latin saltarium, from neuter of Latin saltatorius "pertaining to leaping," from salire "to leap" (see salient (adj.)). The connection between a stirrup and the diagonal cross is perhaps the two deltoid shapes that comprise the cross.
"right-hand-wise, turned toward the right; clockwise," 1771, from Gaelic deiseil, deiseal (adjective and adverb) "toward the south," taken in sense of "toward the right," from deas "right, right-hand; south," cognate with Irish deas, Old Irish dess, des, Welsh dehau, and ultimately with Latin dexter, from PIE root *deks- "right; south." The second element of the Gaelic word is not explained (one old guess, in the Century Dictionary, is a proposed *iul "direction, guidance").