Tragic flaw is a concept often explored in dramatic theater. It holds its roots in ancient Greek tragedies (the word tragedy being derived from the greek tragoida or goat song). One of the standard definitions of a tragedy is that the protagonist of the play is defined by a personality flaw that generally turns fatal. This flaw was called hamartia by the ancient Greeks.
One excellent example of a tragic flaw comes from Macbeth by William Shakespeare. In this play, Lord Macbeth and his Lady both have tragic flaws; weak will and ambition, respectively. These flaws prove to be their undoing, as the murder of the king is eventually traced to them and they are destroyed.