Is fibromyalgia a real condition or a name given to describe otherwise unexplainable symptoms.?

Neither. ? is whether fibromyalgia (FM) is real tissue disorder or merely label for collection of symptoms absent a known cause. Am. College Rheumatology says is real condition w. unknown cause. IMO, FM is a real tissue disorder (soft tissues) with objective findings via Osteopath-type exam of shoulder & pelvic girdles. The clinician should look for signs of sacroiliac joint & thoracic outlet disorders. .
Insightful question. Fibromyalgia is certainly "something"! there is some suggestion that it is a hypersensitivity of the nociceptors (pain receptors) thereby lowering the pain threshhold. It does appear however that many things not easily explained are erroneously dumped into this category thereby using fibromyalgia as a wastebasket. Either way, these individuals suffer and need our help and understanding.
Real. It is a chronic pain syndrome characterized by discomfort that does not have a "known cause" like trauma or inflammation. That being said, the syndrome is certainly real and typically treated with medications that treat neuropathic (originating in nerves) pain. With adequate treatment, patients typically report significantly lower pain scales and lead happier, healthier lives.