barker

Etymology 1

From Middle English berkere; equivalent to bark (“dog noise”) + -er.

noun

1. Someone or something who barks.
   My neighbor's dog is a constant barker that keeps me awake at night.
2. A person employed to solicit customers by calling out to passersby, e.g. at a carnival.
   Bob had amassed a considerable stockpile of double entendres from his days working as a barker for a strip joint.
   […] this fakir was doing a big business, as was shown by the fact that he could afford to hire a barker, who cried continually at the full strength of his lungs: "Come up now, and try your luck! […]" 1893, James Otis, The Adventures of a Country Boy at a Country Fair
   For every dedicated scientist patiently recording atmospheric pressure and wind speed while shivering at high altitudes, there is a carnival barker with a bevy of pretty girls willing to dangle from a basket or parachute down to earth. 2013-06-07, David Simpson, “Fantasy of navigation”, in The Guardian Weekly, volume 188, number 26, page 36
3. A shelf-talker.
4. (video games) A video game mode where the action is demonstrated to entice someone to play the game.
   The barker looks action-packed, but actually playing the game is rather dull
5. (slang, dated) A pistol.
   Parkin, the Oxford Street gunmaker, sent me a brace of barkers in silver mountings, with my initials engraved—good for trade, I imagine. 1969, George MacDonald Fraser, Flashman, page 45
6. The spotted redshank.

Etymology 2

From Middle English barker; equivalent to bark (“surface of tree”) + -er.

noun

1. (historical) A person who removes needed or valuable tree bark, as on a cinnamon or cinchona plantation.
   The profession of barker has been made largely obsolete by the realization that in most cases saplings can be cultivated far more profitably.
2. (obsolete) A tanner.
   The profession of barker has been made largely obsolete by the introduction of more effective tanning agents, but it lives on as a surname.
3. A machine used to remove unneeded bark from wood.
   Run these logs through the barker so we can use them as fence posts.