Search millisecond (msec) millisecond (msec) /-sek′ənd/ [L, mille, thousand; ME, seconde, small part] , one thousandth (10−3) of a second. Tweet Telegram VK Random Words alpha1-antitrypsin collecting tubule choreoathetoid cerebral palsy ethmoidofrontal suture hepatologist brady- acquired magnesium gluconate bacterial food poisoning