Is fibromyalgia a syndrome of some kind?

Yes: Since a syndrome is a combination of body alterations that fit a pattern, that is an appropriate term for fibromyalgia.

Fibromyalgia: Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues. Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain processes pain signals.

Yes: Fibromyalgia is label for constellation of symptoms including chronic pain four quarters of back, restless non-restorative sleep, depression, chronic fatigue & in some cases headaches, panic attacks, fainting, Irritable Bowel Syndrome, Endometriosis, Interstitial Cystitis & chronic widespread pain throughout body. Certain anatomical loci, which oft align w. ligaments & tendons tender to palpation.