† imperiˈosityObs.rare. [f. L. imperiōs-us imperious + -ity.] Imperiousness, arrogance. 1654H. L'Estrange Chas. I (1655) 138 These exorbitances of those sons of Eli..created a very great disgust..and many well enough affected to their Empire, did exceedingly blame their imperiosity.