Top definition
To think you've sent an IM to a friend complaining about someone when actually you sent it to the person you were complaining about.
Jane had a bad case of Mistaken IMendity yesterday - to her horror she accidentally sent an IM to her boss complaining about what a crazy freak he was, instead of sending it to her friend Matt. Total career limiting move!
by maybay July 06, 2007
Happy St. Patties Day!