Word Origin & History
c.1300, "constituting a unit in excess of an even number," from O.N. oddi "third or additional number," as in odda-maðr "third man, odd man (who gives the casting vote)," odda-tala "odd number." O.N. oddi means lit. "point, angle;" related via notion of "triangle" to oddr "point of a weapon," from
P.Gmc. *uzdaz "pointed upward" (cf. O.E. ord "point of a weapon, spear, source, beginning," O.Fris. ord "point, place," Du. oord "place, region," O.H.G. ort "point," Ger. Ort "place"), from PIE *uzdho- (cf. Lith. us-nis "thistle"). None of the other languages, however, shows the O.N. development from "point" to "third number." Used from late 14c. to indicate a surplus over any given sum. Sense of "strange, peculiar" first attested 1580s from notion of "odd one out, unpaired one of three" (attested earlier, c.1400, as "singular" in a positive sense of "renowned, rare, choice"). Odd job (c.1770) is so called from notion of "not regular." Odd lot "incomplete or random set" is from 1897. The international order of Odd Fellows began as local social clubs in England, late 18c., with Masonic-type trappings; formally organized 1813 in Manchester.
in wagering sense, found first in Shakespeare ("2 Henry IV," 1597), probably from earlier sense of "amount by which one thing exceeds or falls short of another" (1548), from odd
(q.v.), though the sense evolution is uncertain. Always treated as a singular, though obviously a plural (cf. news).