Bloody is the adjectival form of blood but may also be used as a swear word or expletive attributive (intensifier) in Britain, Ireland, South East Asia, and Australia. Nowadays it is considered (by most of the population of these countries) to be a very mild expletive, and unlikely to cause offence unless in very religious circles.
Another theory is that it simply comes from a reference to blood, a view that Partridge prefers. However, this overlooks the considerable strength of social and religious pressure in past centuries to avoid profanity. This resulted in the appearance of words that in some cases appear to bear little relation to their source: "Gee" for "Jesus"; "Heck" for "Hell"; "Gosh" for "God"; "dash", "dang" or "darn" for "damn"; "sprinkles" or "shoot" for "shit"; "fick" or "fiddlesticks"; for "fuck"; "witch" for "bitch"; "ninja" for "nigger". These, too, might be considered implausible etymologies if looked at only from the point of view of phonetics. Given the context in which it is used, as well as the evidence of Swift's writing, the possibility that "bloody" is also a minced oath cannot be lightly dismissed.
Although in the 1600s the word appeared to be relatively innocuous, after about 1750 the word assumed more profane connotations in the UK and Commonwealth. The use of bloody in adult UK broadcasting aroused controversy in the 1960s and 1970s but is now unremarkable (as can be seen by the fact that in the Harry Potter movies, which are geared toward children, the character Ron says "bloody hell" many times in all four movies).
The origins of the United Kingdom's objection to "bloody" may be in part due to the connotations of Bloody Mary, most commonly referring to a particularly divisive queen of England notorious for her violent suppression of anti-Catholic views.
The word is seldom used with a negative connotation in the USA, but it is sometimes used to imitate or ridicule the British. Apocryphal extensions of "bloody" are sometimes used in American humor, such as "bloody fuck" or "bloody shit", though the British rarely, if ever, use those phrases. The term "bloody murder" (usually in reference to a particularly loud scream or yell) is also in common use, without any connection with the British usage. The term is usually used when the intention is to mimick an Englishman, though there are some who have adopted it from the British as an everyday term.
There is also "Bloody hell", often pronounced "Bloody 'ell", which can mean "Damn it", or be used as a general expression of surprise or as a general intensifier.
In March 2006 Australia's national tourism commission launched an advertising campaign targeted at potential visitors in several English-speaking countries. The ad sparked a surprise controversy because of its ending (in which a cheerful, bikini-wearing female spokesperson delivers the ad's call-to-action by saying "...so where the bloody hell are you?"). Initially, the Broadcast Advertising Clearance Centre (BACC) required that a modified version of the ad be shown in the United Kingdom, without the word "bloody". However, in May 2006, the Advertising Standards Authority (ASA) ruled that the word "bloody" was not an inappropriate marketing tool and the original version of the ad was permitted to air.