dongle

noun Digital Technology.

1. a hardware device attached to a computer without which a particular software program will not run: used to prevent unauthorized use.
2. Also called wire·less a·dap·ter. 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.

noun

1. computing an electronic device that accompanies a software item to prevent the unauthorized copying of programs