Undergird

Undergird
to form the basis or foundation of : strengthen, support

• "High school students need to understand the paradigms and traditions that undergird social and political institutions." — From a lesson plan at CNNfyi.com, July 3, 2001
  
• "No one argues that a robust U.S. economy is needed to undergird an effective foreign policy." — From an editorial by Jennifer Rubin in the Washington Post, October 9, 2013

DID YOU KNOW?

The English verb "gird" means, among other things, "to encircle or bind with a flexible band."

When "undergird" first entered English in the 16th century it meant "to make secure underneath," as by passing a rope or chain underneath something (such as a ship).

That literal sense has long since fallen out of use, but in the 19th century "undergird" picked up the figurative "strengthen" or "support" sense that we still use. "Gird" and consequently "undergird" both derive from the Old English "geard," meaning "enclosure" or "yard." "Gird" also gives us "girder," a noun referring to a horizontal piece supporting a structure.