To undergo means to experience something, especially something challenging, necessary, or significant that happens to you rather than something you actively choose to do. When you undergo a medical procedure, you're the patient experiencing it. When a building undergoes renovation, it's being changed and improved by others.

The word often appears with experiences that require endurance or patience. A caterpillar undergoes metamorphosis to become a butterfly. A student might undergo training to join the debate team. Scientists might study how materials undergo changes under extreme temperatures.

Notice the difference between undergoing something and simply doing it. You do your homework, but you undergo an examination by the doctor. You take a test, but you undergo a lengthy application process for a special program. The word suggests you're on the receiving end of an experience, moving through something that takes time and may involve difficulty or transformation. When something undergoes change, it's being changed; when you undergo an experience, you're living through it, seeing it through to the end even when it's hard.