Fleming, Sir Alexander
From Longman Dictionary of Contemporary EnglishFleming, Sir AlexanderSir Alexander FlemingFleming, Sir Al‧ex‧an‧der /ˌælɪɡˈzɑːndə $ -ˈzændər/ (1881–1955) a British scientist who discovered penicillin, a substance that is used as a medicine to destroy bacteria (=very small living things related to plants, some of which cause disease)