the.com/swivel chair

means A chair whose seat rotates on a central pivot, letting you turn or swing side to side without getting up or repositioning your feet.

from From 'swivel,' an old mechanical term for a coupling that lets one part turn freely on another — think of a swivel on a fishing line or a ship's gun mount, both designed to pivot without twisting the whole apparatus. The word 'swivel' itself traces back to Old English 'swīfan,' meaning to turn or sweep. Apply that same turning-joint idea to a chair base, and you get furniture that rotates on its own axis — a 19th-century office innovation, with Thomas Jefferson famously tinkering with an early version for his writing desk.