gravis

Gravis is a Latin adjective meaning heavy, weighty, or serious. It appears in classical Latin and has been carried into modern scientific and medical terminology through direct loans. The form and its related nouns such as gravitas and gravity derive from the same semantic core of heaviness and seriousness. In many languages, the word’s lineage is visible in terms that describe weight, force, or solemnity.

One well-known medical usage is the phrase myasthenia gravis, a chronic autoimmune disorder characterized by fatigable weakness of the voluntary muscles. In this name, gravis conveys the severity of the muscle weakness rather than a specific location. The term situates the disease within a family of conditions described by Latin-based nomenclature that emphasize intensity or gravity of symptoms.

Gravis also functions as a descriptive epithet in biological naming. In taxonomy, many species bear the epithet gravis to indicate comparatively large size or weight. This reflects the broader Latin practice of using gravis as a neutral descriptor rather than a diagnosis.

Beyond medicine and biology, gravis is the root of related English terms such as gravity and gravitas, which describe heaviness, importance, or seriousness. These words illustrate the enduring influence of the Latin root on science, philosophy, and everyday language.