Webster's Revised Unabridged Dictionary · 1913

barber pole

barber pole , noun

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.

a pole with red and white spiral stripes; -- usually found outside a barbershop.

Also: barbers pole