A combining element or quasi-prefix occurring in nouns of relationship inherited from OE (step-barn, -child, -doughter, -fader, -moder, -sone) or formed in ME (step-brother, -dame, -sire, -suster). The meaning of the element in OE was 'orphaned, ' as in steop-bearn (-cild), or 'related by remarriage of a parent, ' as in steop-dohtor (-fæder, -modor, -sunu); both meanings continue into ME, though only the latter occurs in the new formations.