Real Dictionary

swivel chair
A swivel chair is a chair whose seat can be turned around a central point to face in a different direction without moving the legs.

swivel chair in American English
a chair whose seat turns around horizontally on a swivel
a chair whose seat turns horizontally on a pivot in the base

swivel chair in British English
noun: a chair, the seat of which is joined to the legs by a swivel and which thus may be spun round