Definition

A central stone in an arch that holds the other stones in place, or something that is essential for supporting a system or structure.

Example

The keystone of the arch was carefully placed to ensure its stability.

Conversation

I just learned that the keystone is the most important stone in an arch.

Really? I didn't know that!

Yeah, it holds everything together, which is pretty fascinating.

That's such a cool fact! It’s interesting how one piece can be so crucial.

Synonyms & Antonyms

Root Explanation

**Keystone** → It is formed from "key" (from Old English *cæg*, meaning a device used to open a lock) and "stone" (from Old English *stan*, meaning a solid mineral matter). The word "keystone" refers to the central stone at the summit of an arch, which holds the arch together, much like a key holds a lock.

Memory Tip

Think of a 'key' that opens a 'lock' and a 'stone' that supports an arch. The keystone is the key stone that holds everything together.

Visually Confused Words