This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

v. Third-person singular simple present indicative form of undergird.

"If hackers earlier this year truly absconded with the detailed software coding that undergirds Google's Gaia password system, as reported by the New York Times this week, the search giant could be facing complex security and liability issues for some time to come, security and tech industry analysts say."

undermine   

undergirded    undergirding    undergirds    undergirt   

beef up    fortify    strengthen    support    back up   

undergirt