The original definition of the word, ‘bloody’ obviously has to do with blood. Bloody refers to the state of being covered, smeared, or running with blood. For example: a bloody cloth, or bloody hands. These are things that are covered with blood.
The term can also be used in reference to something that has the characteristic of leading toward bloodshed or cruelty. For example, a bloody battle, or a bloody coup. These things usually lead to bloodshed.
However, the term ‘bloody’ is used as a swearword in UK and other Commonwealth countries, even though the cuss word is gaining traction in other countries. For example: bloody hell. The term is also used as an intensifier. It is used to make something sound more angry, appealing, exaggerated, etc.