What is "implied consent"

n. 1 The assumed agreement that a person would approve a course of action if asked, when that person is not presently able to be asked. 2 Consent given by virtue of another arrangement.

Implied consent is consent which is not expressly granted by a person, but rather implicitly granted by a person's actions and the facts and circumstances of a particular situation (or in some cases, by a person's silence or inaction). The term is most commonly encountered in the context of United States drunk driving laws.