"Fornication Under Consent of the King" mean the king gives you the right to freak any one you want that your not married to..
The whole thing is a recent urban legend. Except for a brief period in the 1650s fornication has never been a crime in England.
Nearly all these 'acronym' explanations for common words such as f*** and sh** are nonsense. Any good reference dictionary will tell you the origin of such words, invariably considerably earlier than...
Could also be:- For Unlawful Carnal Knowledge.
No, King James was the English king who had the bible translated from latin to english... hence, the King James' version of the bible.