dongle
/ˈdɔŋɡəl/
noun
- A small device that plugs into a computer or other electronic device to enable a specific function, such as wireless connectivity or software security.
- I need a Wi-Fi dongle to connect my desktop computer to the internet.
- She bought a Bluetooth dongle for her old laptop to use wireless headphones.
- The software requires a USB dongle to verify the license.