keystone

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Last year, some 1,000 U.S. troops withdrew from neighboring Niger, ending a nearly decadelong partnership that was the keystone of U.S. counterterrorism operations in the region.

From The Wall Street Journal • Nov. 2, 2025

They "play a central role in the food web, consuming fish and invertebrates and recycling nutrients" and are one of the "keystone species" of their ecosystem.

From Barron's • Oct. 10, 2025

Sunflower sea stars are considered a keystone species, meaning they are critical in regulating the stability and diversity of their ecosystems.

From Los Angeles Times • Aug. 4, 2025

"This is a keystone appointment for us and an integral part of our five-year strategy as we look to achieve sustainable success for our senior men's side," said Tierney.

From BBC • Jul. 21, 2025

For the same color is plain around the keystone of each arch of the Old Bridge, which soars beautifully over the river upstream from the arch.

From "The Left Hand of Darkness" by Ursula K. Le Guin