verb (used with object), un·der·gird·ed or un·der·girt, un·der·gird·ing.
- to strengthen; secure, as by passing a rope or chain under and around: to undergird a top-heavy load.
- to give fundamental support; provide with a sound or secure basis: ethics undergirded by faith.
verb -girds, -girding, -girded or -girt
- (tr) to strengthen or reinforce by passing a rope, cable, or chain around the underside of (an object, load, etc)
v.1520s, from under + gird (v.). Related: Undergirded; undergirding.