Munged meaning : To make repeated changes to a file or data which individually may be reversible, yet which ultimately result in an unintentional irreversible destruction of large portions of the original data. (by extension) To harm, to damage; to destroy. To transform data in an undefined or unexplained manner. To add a spamblock to (an email address). (genealogy) To corrupt a record about an individual by erroneously merging in information about another individual.