a noun-forming suffix occurring originally in loanwords from French (buccaneer; mutineer; pioneer) and productive in the formation of English nouns denoting persons who produce, handle, or are otherwise significantly associated with the referent of the base word (auctioneer; engineer; mountaineer; pamphleteer); now frequently pejorative (profiteer; racketeer).
< French,Middle French-ier (Old French < Latin-ārius-ary as suffix of personal nouns); in some nouns replacing earlier suffixes (see engineer, charioteer) or the French suffix -aire-aire (see musketeer, volunteer)