The word "pachycephalic" refers to animals with thick skulls. Synonyms for this word include "severe-headed," "thick-headed," "dense-skulled," and "flat-headed." These descriptors are commonly used when referring to certain groups of animals, such as dinosaurs like the Triceratops, or certain mammals like the rhinoceros. The term "pachycephalic" can be used in both a scientific context as well as a more general descriptive context. By using synonyms like "dense-skulled" or "severe-headed," writers and speakers can vary their language and avoid repetition while still accurately conveying the intended meaning.