Synonyms of keystone

keystone

noun

ˈkē-ˌstōn 

as in cornerstone

an immaterial thing upon which something else rests

a sense of history is the keystone to the city's draw as a tourist destination

Synonyms & Similar Words

• cornerstone
• basis
• foundation
• bedrock
• root
• base
• justification
• groundwork
• core
• ground
• framework
• underpinning
• footing
• premise
• warp
• support
• theory
• bottom
• essence
• focus
• warp and woof
• infrastructure
• center
• mount
• assumption
• prop
• backbone
• rationale
• kernel
• thesis
• anchorage
• shore
• substratum
• heart
• presumption
• brace
• bed
• substructure
• bulwark
• hub
• warrant
• nucleus
• stay
• buttress
• seat
• presupposition
• supposition
• touchstone
• soul
• eye
• quintessence

Example Sentences

Recent Examples of keystone

The theory of evolution, one of the keystones of modern biological theory, is based on the idea that living things on Earth can be traced back to other preexisting types and that the differences are due to modifications that occurred over successive generations. —Encyclopedia Britannica, 2 Apr. 2026

The birthright citizenship order, which Trump signed on the first day of his second term, is a keystone of his administration’s broad immigration crackdown. —Andrea Castillo, Los Angeles Times, 1 Apr. 2026

This humble dry cleaner, a de jure Chicago landmark, has been photographed by professionals and amateurs alike; has appeared in books, films and music videos; and has become a keystone in conversations about the significance of Chicago’s South Side to this city’s architectural heritage. —Elizabeth Blasius, Chicago Tribune, 18 Mar. 2026

But in the present day, with the glade abandoned, the only hope for construction to stop is for Mabel to find a beaver — a keystone species — that can once again make the area inhabitable. —Wilson Chapman, IndieWire, 2 Mar. 2026