the.com/swivel
The hinge that lets you turn your back without leaving your chair.
means To rotate or pivot around a fixed point, or the joint that allows such rotation.
from From the Old English root behind 'swifan,' to move in a course, kin to 'sweep' — language built for things that turn freely.
Office throneOffice chairs swivel thanks to Charles Darwin's design tinkering.
Fishing fixSwivels stop fishing lines from twisting into knots.
Gun mountSwivel guns rotated on ships long before chairs did.