transitive verb. To support or strengthen from beneath.

To gird round the bottom; gird beneath.

transitive verb. To bind below; to gird round the bottom.

verb. To strengthen, secure, or reinforce by passing a rope, cable, or chain around the underside of an object.

verb. To give fundamental support; provide with a sound or secure basis; provide supportive evidence for.

verb. To lend moral support to.

verb. To secure below or underneath.

verb. make secure underneath

verb. lend moral support to

"Many explanations have been suggested for the greater intolerance of more religiously observant people—that they are more likely to see the world in “we/they” or Manichaean terms, for example, or that moral absolutism—a clear distinction between right and wrong—is incompatible with the skeptical outlook that is said to undergird civic tolerance."

undermine  

back up  beef up  fortify  strengthen  support  

affirm  afford support  attest  authenticate  back  

undergirt  

undergirded  undergirding  undergirds  undergirt