It is commonly used in scientific terms to describe something that is thick, stout, or heavy.
Here are some examples:
* Pachyderm: An animal with thick skin, like an elephant or rhinoceros.
* Pachycephalosaurus: A dinosaur with a thick skull.
* Pachytene: A stage in meiosis where chromosomes are thick and condensed.
* Pachymeningitis: Inflammation of the dura mater, the thick outermost membrane surrounding the brain and spinal cord.