pink slime
n. An industrial meat byproduct consisting of compressed low quality beef trimmings treated with ammonia gas and used as a filler for ground beef.
Examples
2012
Pink slime" will be off the menu this fall for schools in the National School Lunch Program that don't want byproducts containing what's known officially as "lean finely textured beef," the U.S. Department of Agriculture has decided….

Marion Nestle, a professor of nutrition at New York University who wrote the book Safe Food, says the USDA is trying to manage a public relations problem, not a health concern: "Pink slime may be safe, nutritious, and cheap, but it's yucky. It's kind of like pet food.
—Elizabeth Weise, “USDA: Schools can decide if 'pink slime' is used in lunches,” USA Today, March 14, 2012
2012
Baghai believes the market for "fresh and healthy" will only grow in the years ahead, especially with things such as "pink slime" now making ghastly headlines. (Pink slime is the meat filler sprayed with ammonia that is widely used in the U.S. as an unlabelled ingredient in ground beef.)
—Vinay Menon, “Shane Baghai, real estate mogul turned farmer, charges into Toronto’s Burger War,” The Toronto Star, March 12, 2012
2009 (earliest)
Another department microbiologist, Gerald Zirnstein, called the processed beef "pink slime" in a 2002 e-mail message to colleagues and said, "I do not consider the stuff to be ground beef, and I consider allowing it in ground beef to be a form of fraudulent labeling."
—Michael Moss, “Company's Record on Treatment of Beef Is Called Into Question,” The New York Times, December 31, 2009