"trace, impression," O.E. mearc (W.Saxon), merc (Mercian) "boundary, sign, limit, mark," from P.Gmc. *marko (cf. O.N. merki "boundary, sign," mörk "forest," which often marked a frontier; O.Fris. merke, Goth. marka "boundary, frontier," Du. merk "mark, brand," Ger. Mark "boundary, boundary land"), from PIE *mereg- "edge, boundary" (cf. L. margo "margin," O.Ir. mruig "borderland"). The primary sense is probably "boundary," which had evolved by O.E. through "sign of a boundary," "sign in general," "impression or trace forming a sign." Meaning "any visible trace or impression" first recorded c.1200. Sense of "line drawn to indicate starting point of a race" (e.g. on your marks ...) first attested 1887. The M.E. sense of "target" (c.1200) is the notion in marksman (1660) and slang sense "victim of a swindle" (1883). The notion of "sign, token" is behind the meaning "numerical award given by a teacher" (1829). The verb is O.E. mearcian (W.Saxon), merciga (Anglian) "to trace out boundaries," from P.Gmc. *markojanan. Both noun and verb infl. by Scand. cognates. Mark time (1833) is from military drill. Mark-up "amount added by a retailer to cover overhead and provide profit" is from 1920. Marked man "one who is watched with hostile intent" is from 1833.
"unit of money or weight," late O.E. marc, a unit of weight (chiefly for gold or silver) equal to about eight ounces, probably from O.N. mörk "unit of weight," cognate with Ger. Mark, ult. a derivative of mark (1), perhaps in sense of "imprinted weight or coin." Used from 18c. in ref. to various continental coinages, esp. the silver coin of Germany first issued 1875.