To completely discard someone or something that is unwanted, especially in an unceremonious way. The phrase implies that the thing being discarded is being treated as worthless, completely irredeemable, or not worth fixing. The entire design is in danger of getting thrown on the scrap heap if we can't solve the overheating issue. Fred's worked here for 30 years and they just throw him on the scrap heap like that? That ain't right.