What is the definition of a bollard?

A bollard is defined as a strong cylindrical upright, typically found on a pier or along a dock. It serves as a mooring point where boats can tie up, securing them in place to prevent drifting caused by wind or current. The design of a bollard allows it to withstand significant tension from a vessel's mooring lines, ensuring safety and stability in marine operations. This functionality is crucial in maritime environments, facilitating the effective docking and undocking of vessels. The other options refer to different maritime concepts like anchors, securing methods, and knots, which do not align with the definition of a bollard.