negotiate:  The etymological notion underlying negotiate is of ‘not being at leisure’, and hence of ‘being busy’. The word comes ultimately from Latin negōtium ‘business’, which was a compound formed from the negative particle neg and ōtium ‘leisure’ (source of English otiose ). From it was derived the verb negōtiārī ‘do business’, which passed into English as negotiate.
There is some early evidence in the derivatives negotiation and negotiator that the original Latin sense of the word survived into English, but in the verb itself it had already developed via ‘transact business’ and ‘hold business discussions’ to ‘hold discussions’ generally. => otiose
"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.