Is it a bribe that a mafia don dangles in front of his prey?
Is it a Doberman Pinscher-Beagle mix?
Is it Microsoft's slang for bungle?
According to Merriam-Webster on-line -
Pronunciation: 'dä[ng]-g&l, 'do[ng]-
Etymology: perhaps alteration of dangle
a small device that plugs into a computer and serves as an adapter or as a security measure to enable the use of certain software
Traditional uses of a dongles have been for very high-end software to prevent pirated copies. Applications using dongles include for CAD (computer aided drafting, for architects and engineers), rendering, and audio software. Dongles for software have been resisted by consumers because of the need to keep track of another item in addition to the software to be able to use it.
Why this term matters: A dongle can still have a part to play in the encryption or operation of software, but is more commonly used to describe the little piece that plugs into your USB port for wireless hardware like a mouse, a wireless USB hub or a presentation remote control.