Bloody

Meaning the British swear word. There are several theories as to the origin. Here are some options, take your pick.

• God's Blood - A common oath was to swear upon the body or blood of Christ - "God's body" or "God's blood," and this evolved from that.
• Menstruation - A reference to menstrual flow. Lot's of curses refer to bodily functions.
• Aristocrats - Aristocratic heritage is called "blood." Some sources think it comes from "bloody drunk" meaning as drunk as a rowdy young aristocrat.
• Blood - Other sources say that "bloody drunk" means "fired up and ready for a fight."
• Virgin Mary - Many sources claim that the phrase "by Our Lady" became "By'r Lady" (found in Shakespeare) and devolved further to just "bloody." Eric Partridge calls this "phonetically implausible."
• Mary Tudor - The Catholic queen who preceded Elizabeth I and was know for burning Protestants was known as Bloody Mary.