any of a large group of chemical substances, as penicillin or streptomycin, produced by various microorganisms and fungi, having the capacity in dilute solutions to inhibit the growth of or to destroy bacteria and other microorganisms, used chiefly in the treatment of infectious diseases.
any of various chemical substances, such as penicillin, streptomycin, chloramphenicol, and tetracycline, produced by various microorganisms, esp fungi, or made synthetically and capable of destroying or inhibiting the growth of microorganisms, esp bacteria
1894, "destructive to micro-organisms," from French antibiotique (c.1889), from anti- "against" (see anti-) + biotique "of (microbial) life," from Late Latin bioticus "of life" (see biotic). As a noun, first recorded 1941 in works of U.S. microbiologist Selman Waksman (1888-1973), discoverer of streptomycin. Earlier the adjective was used in a sense "not from living organisms" in debates over the origins of certain fossils.
A substance, such as penicillin, that is capable of destroying or weakening certain microorganisms, especially bacteria or fungi, that cause infections or infectious diseases. Antibiotics are usually produced by or synthesized from other microorganisms, such as molds. They inhibit pathogens by interfering with essential intracellular processes, including the synthesis of bacterial proteins. Antibiotics do not kill viruses and are not effective in treating viral infections.