The Collaborative International Dictionary
barber pole \barber pole\, barbers pole \barbers pole\n. a pole with red and white spiral stripes; -- usually found outside a barbershop.
Note: It is often electrically powered, so as to be turning when the barbershop is open for business and stationary when the shop is closed. It symbolizes the practise of surgery, some aspects of which which used to be performed by barbers.
Wiktionary
alt. A type of sign used by barbers, most traditionally a pole with a helix of red and white stripes, in the US including blue, sometimes moving. n. A type of sign used by barbers, most traditionally a pole with a helix of red and white stripes, in the US including blue, sometimes moving.
Usage examples of "barber pole".
Crosetti's barber pole, past all the darkening or darkened shops, the emptying streets, for people were home now from the church suppers, or out at the carnival for the last side show or the last high-ladder diver floating like milkweed down the night.
On the floor in front of the desk was a barber pole, its stripe revolving up and up into infinity.
Windows circled the building at intervals, rising around it in a spiral that made Stan think of the barber pole in front of Mr Aurlette's shop, where he and his dad got their haircuts.
The revolving barber pole was difficult to see because the rain had increased.
But halfway down the block from the bus stop there was a barber pole reflecting a candy cane of light from the window.
The blood swirled through it to a barber pole-like effect, gradually spreading and attenuating to turn the funnel rosy, then pink, then faded to silver, then gone.
What appeared to be a hitching post in front of this building had once been a traditional barber pole with red and white stripes, now faded out.