Bro Patch

Ladies commonly tattoo the lower part of their back and men call it the "tramp stamp". It is rare but in some men they bare the mark of the "Bro Patch" tattoo on the lower part of their back. These men normally carry a fanny pack and almost never take off their shirts.

Hey man, is that a "Bro Patch" I see peeking out of from underneath your shirt?

Fishgills

You have heard of the "Dunlap", the "fupa", the "muffin top", and the "spare tire'. But have you ever heard of "Fishgills"?
Fishgills is the part of the back that goes underneath the armpits. It is not noticeable until one becomes severely overweight and the body and skin start to ooze out resulting in what looks like "Fishgills".

You can't go out in that, your "fishgills" are hanging out!