sexual assault

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Sexual penetration of a person without that person's consent or of a person incapable of consent; rape.
• noun An instance of this.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A physical attack of a sexual nature on another person or a sexual act committed without explicit consent.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a statutory offense that provides that it is a crime to knowingly cause another person to engage in an unwanted sexual act by force or threat