Innocence (or guiltlessness) is a term used to indicate a lack of guilt, with respect to any kind of crime, sin, or wrongdoing. In a legal context, innocence refers to the lack of legal guilt of an individual, with respect to a crime.
Pejorative meaning 
In some cases, the term "innocence" has a pejorative meaning, where an assumed level of experience dictates common discourse or baseline qualifications for entry into another, different, social experience. Since experience is a prime factor in determining a person's point of view, innocence is often also used to imply an ignorance or lack of personal experience.
Loss of innocence 
A "loss of innocence" is a common theme in fiction, pop culture, and realism. It is often seen as an integral part of coming of age. It is usually thought of as an experience or period in a child's life that widens their awareness of evil, pain or suffering in the world around them. Examples of this theme include the song "American Pie" and the novels To Kill a Mockingbird, The Catcher in the Rye, and Lord of the Flies.
- Saul Levitt. "Interpretation of American Pie - analysis, news, Don McLean, Buddy Holly, Ritchie Valens, Rock & Roll". Missamericanpie.co.uk. Retrieved 2011-02-16.