Origin: Germanic Old English prefix
Undergo has 2 different meanings across 1 category:
pass through
"The chemical undergoes a sudden change"
"The fluid undergoes shear"
"undergo a strange sensation"
To go or move under or beneath.
"The submarine will undergo the narrow tunnel to reach the other side of the island."
In plain English: To undergo means to experience something that happens to you, often something difficult or important.
"She will undergo surgery next week to remove her appendix."
Undergo comes from Middle English undergon, which was formed by combining the prefix under- with the verb go. The word originally meant to undermine or ruin something before taking on its current sense of experiencing an event.