Pachydermal is an adjective used to describe the thick or tough skin of animals such as elephants, rhinoceroses, and hippopotamuses. Some synonyms for pachydermal are thick-skinned, leathery, calloused, or toughened. Other alternatives may include rough, hard, rugged, or unyielding. These words convey a similar meaning to pachydermal and can be used interchangeably in many contexts. For instance, describing a person as having a "thick skin" can be used as a synonym for pachydermal, emphasizing their ability to handle criticism or rejection. Overall, these synonyms help diversify the language used in writing about animals or describing different physical characteristics.