overspreading adjective 1noun 1forms 3 adjective1 •Rampant; encroaching.The third part of practice hath divers branches, but one principal root in these our times, which is the vast and overspreading ambition and usurpation of the see of Rome; […] — 1627 noun1 •That which spreads over something else. formsoverspreadings · more overspreading · most overspreading