resting adjective Etymology: Middle English, from present participle of resten to rest, repose 1.: not in growing condition : not physiologically active : dormant, quiescent < a resting lily bulb > < resting nerve cells > also: of, relating to, or marked by dormancy < a resting period > < resting stages > 2.: not undergoing or marked by mitosis or other form of division though otherwise physiologically active < a resting stage >