a hardware device attached to a computer without which a particular software program will not run: used to prevent unauthorized use.
Also called wireless adapter. a device that can be plugged into a USB port to enable wireless access from a computer to an external Wi-Fi device, as a mobile phone, or to the Internet, via high-speed broadband, or to enable wireless connectivity in a printer or other peripheral.
Origin of dongle
First recorded in 1980-85; probably an arbitrary coinage