linchpin
🇺🇸
/ˈlɪntʃpɪn/
🇬🇧
/ˈlɪntʃpɪn/
The most important person or thing in a group or plan that holds everything together.
In our team, Sarah is the linchpin because she keeps everyone on track.
私たちのチームでは、サラは全員を正しい道に保つため、要の人物です。