Why was "tantrum" trending last week?
1590s, "businessman," from Latin negotiator "one who carries on business by wholesale," from negotiatus, past participle of negotiari (see negotiation). Meaning "one who carries on negotiations" is from c.1600.
"to communicate in search of mutual agreement," 1590s, back-formation from negotiation, or else from Latin negotiatus, past participle of negotiari. In the sense of "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.