Do you know a funny way to describe the 6-pack of a person who is pretty fat and doesn't have his/her abs well developed (his/her abs are in fact covered by fat?) Could I say "fat-pack" or something like this?
Thanks a lot!
Yes, you could, but you're not describing this person's six-pack. He or she doesn't have a six-pack. That's not a term for abs in general. It refers only to the appearance of well-developed, well-defined muscles in an abdomen with little or no fat.
Everyone has abdominal muscles, but unless yours are showing, we generally wouldn't say that you have "abs" or a "six-pack" of any sort at all. "Fat abs" sounds like you have a visible six-pack but each of the individual lumps is flabby-looking or puffy.