Definition of -eer in English:

-eer

suffix

  • 1(forming nouns) denoting a person concerned with or engaged in an activity.

    ‘auctioneer’
    ‘puppeteer’
  • 2(forming verbs) denoting concern or involvement with an activity.

    ‘electioneer’
    ‘profiteer’

Origin

From French -ier, from Latin -arius; verbs ( -eer) are often back-formations (e.g., electioneer from electioneering).