backstory

noun

Etymology: From back- (prefix meaning ‘in, into, or towards the past’) + story.

1. The previous experiences and life of a person, specifically (narratology, especially in film, television) a character in a dramatic work.

   “What’s the backstory of our new colleague?”

   “These backstories cast the characters' behavior in a new light: of course Gertrude would promptly marry the man who saved her from abuse; of course Ophelia would be desperate and indiscreet in seeking Hamlet's love.”

2. A fictitious account of a person's history designed to conceal their actual history and motives.