I was thinking about the way "innocent" is often used (in both casual and moderately formal contexts) to mean "sexually inexperienced/oblivious", and came to the conclusion that using the phrase in such a way would imply that persons who have some degree of sexual experience are guilty of some trespass. Because this is an idea which does not align with my beliefs, I am trying to remove this phrase from my personal vocabulary.
Before I do so, I was wondering about the origin of the usage of the word "innocent" in this manner. Can anyone shed some light on the history of this usage? Or, if that is a question that is too broad to answer here, what sort of resources would I look into if I wanted to learn more about the history of a word's usage in a particular manner?