Definition of family romance in US English:

family romance

noun

  • 1A romantic story centred on a particular family.

  • 2Psychoanalysis (in Freudian theory) a childhood fantasy characterized by the belief that one is not the child of one's parents, but that one is in fact of royal or high birth.

Origin

Early 19th century; earliest use found in Sydney Morgan (bap. 1783, d. 1859), novelist and socialite.