A child (plural form is children) is someone who is not an adult yet, or a person who has not reached puberty, which usually happens in adolescence. Sometimes, teenagers (between puberty and legal adulthood) are also called children. A baby that is not yet born is often called a child, too. A person can be called his or her parent's child, no matter how old he or she is. Some synonyms for the word 'child' are "kid", "toddler", "bairn", "youngster", "boy" or "girl, lad" or" lass", and" youth. "