1. To go or move below or under.
2. To be subjected to; to bear up against; to pass through; to endure; to suffer; to sustain; as, to undergo toil and fatigue; to undergo pain, grief, or anxiety; to undergothe operation of amputation; food in the stomach undergoes the process of digestion. Certain to undergo like doom. (milton)
Origin: AS. Undergan. See Under, and Go.