Keystone

Definitions

1. A census-designated place in Colorado.
2. The top stone of an arch.
3. A city and town in Iowa.
4. Something on which other things depend for support.
5. A ghost town in North Dakota.
6. A native or resident of the American state of Pennsylvania.
7. A town in South Dakota.
8. A retail price that is double the cost price; a markup of 100%.
9. The combination of the shortstop and second baseman.

Equivalents

Examples

“The tunnel, which is 1,000 yd. long, had been closed to passenger traffic since November 17, 1949, after some of the keystones had worked loose.”

“Tension between empirical and theoretical knowledge is keystone to sociological and to organizational theories, as early as in Marx's and Weber's frameworks.”

CEFR level