A pronged connecting device which fits into a mating socket, especially an electrical one.

“I pushed the plug back into the electrical socket and the lamp began to glow again.”

Any piece of wood, metal, or other substance used to stop or fill a hole.

“Pull the plug out of the tub so it can drain.”

A flat oblong cake of pressed tobacco.

“He preferred a plug of tobacco to loose chaw.”

To stop with a plug; to make tight by stopping a hole.

“He attempted to plug the leaks with some caulk.”

To blatantly mention a particular product or service as if advertising it.

“The main guest on the show just kept plugging his latest movie: it got so tiresome.”

To persist or continue with something.

“Keep plugging at the problem until you find a solution.”