unlockbutton
nounUK /ʌnˈlɒk ˈbʌtən/
US /ʌnˈlɑːk ˈbʌtən/
A button you press to open a lock.
Press the unlockbutton to open the car door.
OTHER MEANINGS
2. A button on a phone or remote that turns off a security lock.
Tap the unlockbutton on the screen to use your phone.
3. A button that lets you out of a locked place.
The unlockbutton by the gate let the kids out of the yard.
4. A button that frees something stuck or closed.
He hit the unlockbutton to open the stuck drawer.