auctioneer (n.)

"public sale in which each bidder offers more than the previous bid," 1590s, from Latin auctionem (nominative auctio) "a sale by increasing bids, public sale," noun of action from past-participle stem of augere "to increase" (from PIE root *aug- (1) "to increase"). In northern England and Scotland, called a roup. In the U.S., something is sold at auction; in England, by auction.

noun word-forming element meaning "one who" (operates, produces, deals in); Englished form of French -ier, from Latin -arius, -iarius; compare -ary. Usually in English words of more recent borrowing from French; older words tend to keep -ier.

"to try to influence an election by public speaking, solicitation of votes, etc.; to work for the success of a candidate or of a party in an election," 1760 (implied in verbal noun electioneering), from election, probably on model of auctioneer, as the verb engineer was not yet in use.