Other forms: barkers
A barker is somebody who shouts outside a show to draw a crowd in. The fairground barker, a barker on the door, barking for the sideshow.
It is fairground and circus vocabulary and belongs mostly to the past, though the job survives outside restaurants and clubs in tourist streets. The barker's patter is the continuous improvised speech, and the skill was real. Note that a barker is also simply a dog that barks a great deal; and that the word is one of a small set — barker, spieler, tout — for people paid to talk strangers into things.
1nounbarkerSomebody who shouts to draw a crowd to a show.
“A barker outside the circus tent shouted, 'Roll up, roll up, come and see the lions!'”
barker is a show caller.
BARKer → he BARKs to pull the crowd in
He barks outside the tent like a dog, loud enough to pull the whole street in.
hooks ontobark
The word is bark plus -er, and bark for a dog is Old English beorcan, imitative of the sound. The showman was named after the dog rather than the other way round.
Middle English
berkere
English, today
barker
From Middle English berkere; equivalent to bark + -er.
Etymology from Wiktionary, CC BY-SA