From Glossary of Meteorology
A phenomenon investigated experimentally and theoretically by G. I. Taylor in which the relative motion of a homogeneous rotating liquid tends to be the same in all planes perpendicular to the axis of rotation.
For example, if a sphere is introduced as an obstruction, the fluid flows around it as if it were a cylinder extending the entire depth of the fluid parallel to the axis of the system. It is due essentially to the presence of very geostrophic, homogeneous conditions so that the thermal wind is zero. It occurs at very low values of the Rossby number.