noun. ['ˈkiːˌstoʊn'] the central building block at the top of an arch or vault.
- building block
Words that Rhyme with Keystone
Example sentences of the word keystone
1. Noun, singular or mass
Beavers are so important in ecology that they are known as a keystone species.
Because they chow down on urchins, sea otters are considered "keystone predators."
Quotes containing the word keystone
1. The philosophic outlook rises above all sectarian controversy. It finds its own position not only by appreciating and synthesizing what is solidly based in the rival sects but also by capping them all with the keystone of nonduality.
- Paul Brunton, The Notebooks of Paul Brunton
noun. ['ˈkiːˌstoʊn'] a central cohesive source of support and stability.