love child 
noun
A child born to parents who are not married to each other.The Hollywood actress and her lover want their love child to be born in Africa because it is the cradle of civilization....
- Meantime, Nola gives birth to their love child Jason, a son born blind because, she thinks, of her exposure to mercury fillings.
- And so it began, my phase of daydreams about the Gypsies who had dropped me off at the door of the squares, or about the young woman with a halo of ash blonde curls, dying of consumption and imploring my parents to take care of me, her love child.