pachycephalic adjective2 •Characteristic of or characterized by pachycephaly.Virchow stated that premature fusion of this suture results in pachycephalic deformity. — 1956 •Thick-skulled; stupid and imperceptive.The fact that the Adams patent should ever have received recognition in the temple of justice proves that a judge may be learned in the law, but woefully pachycephalic in matters scientific. — 1880 formsmore pachycephalic · most pachycephalic