Definition : sexual contact usu. that is forced upon a person without consent or inflicted upon a person who is incapable of giving consent (as because of age or physical or mental incapacity) or who places the assailant (as a doctor) in a position of trust see also rape Sexual assault in its most serious forms (often classified as first degree sexual assault) involves nonconsensual sexual penetration. In its less serious forms it may be the equivalent of statutory rape.