"the running of races, the occupation or business of arranging for or carrying on races," originally especially horse races, 1670s, verbal noun from race (v.).
1590s, "to communicate with another or others in search of mutual agreement," a back-formation from negotiation, or else from Latin negotiatus, past participle of negotiari "carry on business, do business," from negotium "a business, employment, occupation, affair (public or private)," literally "lack of leisure," from neg- "not" (from PIE root *ne- "not") + otium "ease, leisure," a word of unknown etymology.
Transitive sense of "arrange for or procure by negotiation" is from 1610s. In the sense of "handle, manage, tackle successfully" (1862), it at first meant "to clear on horseback a hedge, fence, or other obstacle" and "originated in the hunting-field; those who hunt the fox like also to hunt jocular verbal novelties" [Gowers, 1965]. Related: Negotiated; negotiating.
1580s, "one who directs or controls," agent noun from manage. Specific sense of "one charged with conducting a house of business or public institution" is from 1705.
late 14c., verbal noun from count (v.). Counting-house "room or building set aside for bookkeeping, correspondence, business transactions," is from mid-15c.
early 15c., "one appointed to perform some business by a commission from a proper authority," from Anglo-French commissionaire, from or on the model of Medieval Latin commissionarius "one entrusted with a commission," from commissionem "act of committing," in Medieval Latin "delegation of business" (see commission (n.)).
Meaning "member of a commission" is from 1530s, especially "person elected to manage the affairs of a municipality." Short form commish is attested by 1910 (earlier it was short for commission).
early 14c., "fact of holding or possessing;" mid-14c., "a being employed in something," also "a particular action," from Old French occupacion "pursuit, work, employment; occupancy, occupation" (12c.), from Latin occupationem (nominative occupatio) "a taking possession; business, employment," noun of action from past-participle stem of occupare (see occupy). Meaning "employment, business in which one engages" is late 14c. That of "condition of being held and ruled by troops of another country" is from 1940.