keystone
keystone Lexical Profile
keystone Game Scores & Validity
• noun
The fundamental principle, element, or core component on which an entire system, policy, or process depends.
"Freedom of speech remains the absolute keystone of any functioning democratic society."
A biological species or ecological entity that exerts a disproportionately large impact on its surrounding environment, crucial for maintaining the structure of an ecological community.
"As an apex predator, the sea otter acts as a keystone by keeping the sea urchin population in check and protecting the kelp forests."
The central, wedge-shaped stone at the apex of a masonry arch or vault that locks all the other stones into position.
"The master mason carefully lowered the keystone into place, ensuring the magnificent stone arch could finally support its own weight."
• Rhymes for keystone
Word Origin & Etymology
First recorded in the mid-1600s as a literal translation of the Italian 'chiave' or Latin 'clavis', formed by compounding 'key' and 'stone' to describe the central stone that locks a masonry arch.
Usage Trend
Historical frequency of usage in published text.