Definitions

1. noun

Any of various large, hoofed mammals, especially the elephant, rhinoceros, and hippopotamus

“The zoo is home to several pachyderms, including an elephant and a rhinoceros.”

2. noun

A person who is stubbornly inflexible or obstinately attached to a particular opinion or policy

“He was accused of being a pachyderm, unwilling to compromise on the proposed bill.”