in medicine, any circumstance which indicates the existence, nature, or stage of a disease. Pain, waking, drowsiness, convulsions, impregnable urine, difficulties of breathing and swallowing, coughs, distillates, nausea, thirsts, swoonings, faintings, looseness, stiffneisses, dryness and blackness of the tongue, are the principal symptoms of diseases. See Medicine, no. 21, and 58.