Un`der*go" (?), v. t. [imp. Underwent (?); p. p. Undergone (?; 115); p. pr. & vb. n. Undergoing.] [AS. undergān. See Under, and Go.] 1. To go or move below or under. [Obs.]

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.

3. To be the bearer of; to possess. [Obs.]

Their virtues else, be they as pure as grace,
As infinite as man may undergo.

4. To undertake; to engage in; to hazard. [Obs.]

I have moved already
Some certain of the noblest-minded Romans
To undergo with me an enterprise.

5. To be subject or amenable to; to underlie. [Obs.]

Claudio undergoes my challenge.

Un`der*go" (?), v. t. [imp. Underwent (?); p. p. Undergone (?; 115); p. pr. & vb. n. Undergoing.] [AS. undergān. See Under, and Go.] 1. To go or move below or under. [Obs.]

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.

3. To be the bearer of; to possess. [Obs.]

Their virtues else, be they as pure as grace,
As infinite as man may undergo.

4. To undertake; to engage in; to hazard. [Obs.]

I have moved already
Some certain of the noblest-minded Romans
To undergo with me an enterprise.

5. To be subject or amenable to; to underlie. [Obs.]

Claudio undergoes my challenge.

• (transitive) To experience; to pass through a phase.
       The project is undergoing great changes.
  
• (transitive) To suffer or endure.
       The victim underwent great trauma.
       She had to undergo surgery because of her broken leg.