plug

As nouns the difference between plug and plughole

is that plug is a pronged connecting device which fits into a mating socket while plughole is the hole at the bottom of a sink or tub, which can be blocked using a plug.

As a verb plug

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

As nouns the difference between plug and multiplug

is that plug is (electricity) a pronged connecting device which fits into a mating socket while multiplug is an electric device that allows more than one plug to connect to a single socket by containing multiple similar sockets; particularly for mains electricity.

As a verb plug

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