“Mainstay”
In the rigging of any sailing yacht but particularly the tall ships of old, the mainstay was a vital rope running from the maintop to the foot of the foremast, providing essential support to the mast and the ship’s structure. Without it, the vessel’s stability was compromised.
Today, “mainstay” describes something or someone that serves as a foundational or indispensable element in a system or organisation.

Written by Lindsey
