"msagro" is oragsm spelled backwards. Thus it is the opposite of an orgasm.
It is used to describe a person who is excessively ugly. A person so ugly, that they cause the speaker to have a "msagro"
The insult "msagro" is often followed by the phrase "Thank you. My pants are now cleaner than they were before."
"Did you see that girl across the street? Total msagro!"
*Walking past an excessively ugly person*