n. a skeletal muscle relaxant that inhibits transmission of synaptic reflexes at the spinal cord level. A GABAB receptorgabab-receptor agonist, it is often used in the treatment of reversible spasticity associated with multiple sclerosis or spinal cord injury. Baclofen has also been found to inhibit the rewarding properties of drugs with abuse potential (opiates, cocaine, etc.). U.S. trade name: Lioresal.