A hollow seen on the radial aspect (the thumbside) of the dorsum (the back) of the wrist when the thumb is extended fully. The reason that it is called the anatomical snuffbox is that snuff (powdered tobacco) could be put there and then inhaled.

A hollow seen on the radial aspect of the wrist when the thumb is extended fully; it is bounded by the prominences of the tendon of the extensor pollicis longus posteriorly and of the tendons of the extensor pollicis brevis and abductor pollicis longus anteriorly. The radial artery crosses the floor which is formed by the scaphoid and the trapezium [..]