Hypoglossal neuropathy: Disease of the hypoglossal nerve, the twelfth cranial nerve. The twelve cranial nerves, the hypoglossal nerve included, emerge from the skull, as opposed to the spinal nerves which emerge from the vertebral column. The hypoglossal nerve supplies the muscles of the tongue. Paralysis of the hypoglossal nerve affects the tongue. It impairs speech (the speech sounds thick) and causes the tongue to deviate toward the paralyzed side. In time, the tongue diminishes in size (atrophies).
From the Greek "hypo-", under + "-glossal" from A"glossa", the tongue = under the tongue.