You know there are lots of words like this. What has happened is semantics. It is intentional and it is part of the reason everyone is so divided about everything. Fag used to be a Cigarette. Gay used to be happy. Cheater used to mean an officer to look after a kings land. Egregious used to mean extremely good. Girl used to mean a young child or person of either sex.
http://mentalfloss.com/article/61876/11-words-meanings-have-changed-drastically-over-time
These are just a few I have found looking. My wife and I talk about this subject often because in legal term words have a defined definition and that definition is written down to make sure everyone understands. In Blacks legal Dictionary you will find out how many words have exact meanings that are contrary to what you thought they meant!