A clog is a blockage in plumbing such as hairballs, grease or other clumping materials. It is generally removed by use of a plunger or chemical drain cleaner.
A clog is a shoe with a rigid, often wooden, sole. Clogs were widely worn by workers as protective clothing in factories, mines and farms. In more developed countries they have been replaced by steel toe-capped boots.
A form of tap dancing using clogs is called clogging.
