“bloody” which is an expletive adjective (read: swear word) as in ‘bloody hell’, or ‘bloody nuisance’ and it happens to be one of my favourites to use (funny enough, if I get hurt I swear in Afrikaans- so much more descriptive!).
Brewer’s 1870 dictionary of phrase and fable explains that the use of the word ‘bloody’ in this sense “…..arose from associating folly or drunkenness, etc., with what are (were) called ‘Bloods’, or aristocratic rowdies….” Brewer explains also that this usage is in the same vein as the expression ‘drunk as a lord’, (a lord being a titled aristocrat in British society). Rowdy aristocrats were called ‘Bloods’ after the term for a thoroughbred horse, a ‘blood-horse’ (as in today’s ‘bloodstock’ term, meaning thoroughbred horses). Clearly, the blood-horse metaphor captures both the aristocratic and unpredictable or wild elements of this meaning. The use of blood in this ‘aristocratic’ sense would have been reinforced by other similar metaphors: ‘blood’ was and still is a term used also to refer to family descent, and appears in many other lineage-related expressions, such as ‘blood is thicker than water’ (people are more loyal to their family members than to other people) and ‘blue blood’ (royalty or aristocratic people – an expression coming into England from France where ‘sang blue’ means of high aristocratic descent, the notion originating in Spain when it was believed that pre-Moorish old Spanish families had blue blood whereas the common people’s blood was black. The blue blood imagery would have been strengthened throughout Western society by the idea of aristocratic people having paler skin, which therefore made their veins and blood appear more blue than normal people’s.) The modern expression ‘bloody’ therefore derives from an old expression of unpredictable or drunken behaviour, dating back at least to the early 19th century.
I have come to the conclusion that I must be a blue blood- I have the pale skin and veins to prove it too! Waaaaahahahahaha!