A gland is a type of stuffing box that is used to seal a reciprocating or rotating shaft against a fluid. The most common is the head of a tap called the faucet where the glad is usually packed with string which has been soaked in similar grease or tallow. The gland nut allows the packing material to be compressed to form a watertight seal and prevent the water from leaking up the shaft when the tap is turned on.
The gland at the rotating shaft of a centrifugal pump may be packed in a similar way and the graphite grease is used to accommodate continuous operation. Linear seal around the piston rod of a double acting steam piston is also known as a gland and is particularly in marine applications likewise the shaft of a hand or wind pump is sealed with a gland where the shaft exits the borehole.
Some other types of sealed connections are without moving parts and also sometimes they are called glands. For example, if a cable fitting or gland connects to a flexible electrical conduit to an enclosure, bulkhead or machine facilities assembly and prevents gas or liquid ingress.