solokey
nounUK /ˈsəʊləʊkiː/
US /ˈsoʊloʊkiː/
A small key that works by itself to open one lock.
She kept the solokey in her pocket so she could open the garden gate.
OTHER MEANINGS
2. A password used alone, without a second step, to log in.
The old site still lets you sign in with just a solokey.
3. A musical key played by one instrument without accompaniment.
The pianist chose a solokey for the quiet opening.
4. A single button or switch that controls one function on a device.
Press the solokey on the remote to turn on the lamp.