Linchpin
A linchpin is a person or thing vital to an enterprise or organization. Our word of the day has its origin in the Middle English word ‘lync’ (LINK) which means axle and the word pin. Lynchpin was used to refer to a pin or bolt used to secure an axle in place, preventing the wheel from coming loose. In time, the word came to be used metaphorically to refer to something or someone who needs to remain in place to keep something together. Here’s an example of linchpin in use: My van was used so frequently in our company that it became something of a linchpin. Without it, we would have never been able to take care of so many transportation needs.