I haven't heard of this term until recently, and I do think the name is pretty stupid, but with the exposure of Michelle Obama's finely toned arms, more and more people are talking about the "Batwing" procedure. "Batwing" is slang for the loose skin of the upper arm that many people get with aging and weight loss. We have two surgeries to treat it: liposuction and brachioplasty. I'm not a big fan of either procedure, since liposuction doesn't tighten up the arm skin and a brachioplasty results in a long scar. Nevertheless, I will often liposuction the upper arms of people who complain about excessive fat there. It can be effective.
Maybe we can come up with a better slang term someday.