mastermind
🇺🇸
/ˈmæstərmaɪnd/
🇬🇧
/ˈmɑːstəmaɪnd/
The person who comes up with the main ideas for a plan or project.
The mastermind of the project was the one who convinced everyone to join.
To be the main planner of a project or event.
He masterminded the whole event, making sure everything went smoothly.