What are some slang terms for fat?

Some slang terms that refer to fat would include flab, lard, or poundage. If you are talking about a fat person, you might say chubby, pudgy, or flabby. Depending on which Word you choose, you might be insulting or just teasing in a friendly manner. "He's a chubby fellow," would be a friendly way of saying someone is overweight. Saying "He's a lard-arse," would be an insult.