Indeed, the adult child of the parent. The word child in English can refer to a very young person, but also commonly refers to the progeny of a person, as in th

Indeed, the adult child of the parent. The word child in English can refer to a very young person, but also commonly refers to the progeny of a person, as in the comment you were responding to, where child was used in reference to the parent that was also referred to in the comment.