cornerstone
UK: ˈkɔːnəstəʊn | US: ˈkɔːrnərstoʊn
n. 1. A stone that forms the base of a corner of a building, often laid ceremonially.
n. 2. An indispensable and fundamental basis or element of something.
The word "cornerstone" combines "corner" (from Old French cornière, meaning "angle" or "projecting point") and "stone" (from Old English stān, meaning "rock"). Historically, a cornerstone was the first stone laid in a building's foundation, symbolizing stability and importance. Over time, it evolved metaphorically to represent the foundational or most essential part of any system or idea.
The mayor laid the cornerstone of the new library in a formal ceremony.
Trust is the cornerstone of a healthy relationship.
The constitution serves as the cornerstone of the nation's legal system.
The scientist’s theory became the cornerstone of modern physics.
Without honesty, the team’s collaboration lacked a cornerstone.