Verticity is a term used to describe the tendency of a fluid to rotate in a spiral manner. It can also refer to the degree of rotation within a fluid. Some synonyms for verticity include vorticity, helicity, rotation, spin, and swirl. Vorticity and verticity are often used interchangeably, with vorticity being the more commonly used term. Helicity is a more specific term which refers to the potential for a fluid to produce a helix or screw-like motion. Rotation and spin describe the movement of an object around its own axis or pivot point. Swirl is a more general term that describes any circular or twisting motion in a fluid or object.