Pretty much the same thing as breast. It is usually used by uneducated people with speech impediments, with the exception of the habit of the modern world interfering with fluent English. Some people also use this word to mock others, such as the special girl down the street, or the 'just learning to speak' two year old. Overall, breast or breastasis are loved by millions world wide.
A person you hate intensely not because they deserve such hatred but because they serve as a focus for your general hatred. A healthy way to dispense with excess animosity.
Jake's not really that big an asshole. He just serves as my hate sink.