wall wart

n. A small power-supply brick with integral male plug, designed to plug
directly into a wall outlet; called a wart because when installed on a power
strip it tends to block up at least one more socket than it uses. These are
frequently associated with modems and other small electronic devices which
would become unacceptably bulky or hot if they had power supplies on board
(there are other reasons as well having to do with the cost of UL
certification).

