To undergo is to experience something.(verb)
When you are required to have surgery, this is an example of a situation where you undergo surgery.
See undergo in Webster's New World College Dictionary
See undergo in American Heritage Dictionary 4
transitive verb un·der·went (-wĕntˈ), un·der·gone (-gônˈ, -gŏnˈ), un·der·go·ing, un·der·goes (-gōzˈ)
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