The phrase "unimaginable suffering" means experiencing extreme pain or distress that is difficult to comprehend or think about because it is so intense or devastating. Full definition
Too often those «puppies in the window» came from puppy mills, which are the source of unimaginable suffering for the dogs used for breeding. (crossroadscampus.org)
Victor Frankl, a psychologist and a former Jewish prisoner in a Nazi concentration camp, explains in his book Man's Search for Meaning, that human beings can endure unimaginable suffering if they see a meaning in it. (topresume.com)
It tells the stories of six extraordinary young people who, despite almost unimaginable suffering and adversity, exceeded almost everyone's expectations. (sleepoutamerica.org)