keystone

Meanings

Noun

• The top stone of an arch.
• Something on which other things depend for support.
• A native or resident of the American state of Pennsylvania.
• A retail price that is double the cost price; a markup of 100%.
• The combination of the shortstop and second baseman.

Verb

• To distort (an image) by projecting it onto a surface at an angle, which for example causes a square to look like a trapezoid.
• To double the cost price in order to determine the retail price; to apply a markup of 100%.

Origin

• key + stone
• Definition 4 (retail) perhaps originated in the jewelry industry in the magazine called "Jewelers' Circular-Keystone"
• Source: https://english.stackexchange.com/questions/341864/what-is-the-source-of-the-word-keystone-in-reference-to-pricing-a-product