The phrase "unimaginable amount" means a quantity or number that is so big or large, it is difficult or impossible to imagine or comprehend. Full definition
Eventually, and sometimes uproariously, this escalates into an extremely dangerous business, as Seal gets addicted to the thrill of the game and the allure of unimaginable amounts of cash. (seattleweekly.com)
I am including a chapter on a dear friend of mine who lost almost unimaginable amounts of weight, without dieting, just by eating whole foods, and who is sharing her story in this book. (levanacooks.com)
I was bruised and bleeding and in unimaginable amount of pain with each latch. (romper.com)