Definition: The word "sourdough" refers to a type of bread that originates from France. It's made with rye flour, sourdried tomatoes, and olive oil. The term was popularized in 19th century England as a way to explain sourdough bread in its raw state. In more modern context, it describes a type of bread traditionally used in Germany for sandwiches or toasted pastries. It's often known as "Hummel" or "Lichtenburg". In some parts of the world, sourdough is also known as "Bacon" because it is made from rye flour and can be used to make sausage-like dishes. The word 'sourmilk' in Christian context has been interpreted differently. Some believe that sourmilk is a form of milk or dairy product, while others refer to the taste of something fermented. In the Bible, this term was often used metaphorically by Jesus Christ to describe the wine he drank during his crucifixion as an emblem of his death. The definition might be that it's not specific in the sense that it represents a substance. It is a metaphorical way to express a different concept or idea.