Fleming, Sir Al‧ex‧an‧der /ˌælɪɡˈzɑːndəʳ $ -ˈzæn-/
(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) [TahlilGaran] Dictionary of Contemporary English ▲