pachyderma

/ˌpækɪˈdɜrmə/
noun
  1. Abnormal thickening of the skin, often as a symptom of a medical condition.
    • The dermatologist explained that pachyderma is different from normal calluses.
    • The patient's pachyderma was a sign of a rare genetic disorder.
    • Chronic lymphedema can lead to pachyderma in the affected limbs.