(ecology) A species that exerts a large, stabilizing influence throughout an ecological community, despite its relatively small numerical abundance.

(business, marketing) A pricing method where the price is doubled at each level of distribution.

The official nickname for the Commonwealth of Pennsylvania in the United States of America.

plural of keystone corner

(informal) A bungling, incompetent policeman.

plural of Keystone Kop

Alternative form of Keystone Cop

plural of Keystone Cop

(mineralogy) A hexagonal-dipyramidal mineral containing hydrogen, iron, magnesium, nickel, oxygen, and tellurium.