function key
nounUK /ˈfʌŋkʃən kiː/
US /ˈfʌŋkʃən kiː/
A special button on a computer keyboard that does a certain job when you press it.
Press the F1 function key to open the help menu.
OTHER MEANINGS
2. A key labeled F1 through F12 on a computer keyboard used to trigger commands.
The function keys sit in a row at the top of the keyboard.
3. A key on a device that performs a predefined action rather than typing a character.
He pressed the function key to turn on the laptop's screen brightness.
4. A programmable button on some electronic instruments that runs a set task.
The synthesizer's function key switched the sound to piano.