Definition of "pachyderm"

(obsolete, zoology) A member of the obsolete taxonomic order Pachydermata, grouping of thick-skinned, hoofed animals such as the rhinoceros, hippopotamus, elephant and tapir.

(informal) An elephant  examples

(idiomatic) A person with thick skin; someone who is not affected by or does not care what others say about them.  examples

(idiomatic) Someone who is insensitive.  examples