mainkey
nounUK /ˈmeɪnkiː/
US /ˈmeɪnkiː/
The most important key that opens the main lock.
Dad keeps the mainkey on a hook by the front door.
OTHER MEANINGS
2. The most important button on a keyboard or device.
Press the mainkey to start the machine.
3. The central or leading idea in a plan or story.
The mainkey of the lesson was to be kind.
4. A key note in a piece of music that the song is built around.
The song stays in the mainkey from start to finish.