statutory rape

Definition from Nolo’s Plain-English Law Dictionary

Sexual intercourse with a person who has not yet reached the age of consent (determined by state law), whether or not the sexual act is against that person's will. In many states, "Romeo and Juliet" trysts, in which the male and female are young and there is little or no difference in age between them, are punished less severely than when the victim is significantly younger than the perpetrator. When the victim is not only below the age of consent, but also a child (as defined by state law), the offense may be rape or child molestation.

Definition provided by Nolo’s Plain-English Law Dictionary.