From Wikipedia:
In common law jurisdictions, statutory a is nonforcible sexual activity in which one of the individuals is below the age of consent (the age required to legally consent to the behaviour).[1][2] Although it usually refers to adults engaging in sexual contact with minors under the age of consent, it is a generic term, and very few jurisdictions use the actual term statutory a in the language of statutes.[3] In statutory a, overt force or threat is usually not present. Statutory a laws presume coercion because a minor or mentally disabled adult is legally incapable of giving consent to the act.
Different jurisdictions use many different statutory terms for the crime, such as sexual assault, a of a child, corruption of a minor, unlawful sex with a minor,[4] carnal knowledge of a minor, sexual battery,[5] or simply carnal knowledge. The terms child sexual abuse or child molestation may also be used, but statutory a generally refers to sex between an adult and a minor past the age of puberty, and may therefore be distinguished from child sexual abuse.[1][6] Sexual relations with a prepubescent child is typically treated as a more serious crime.[1][6]