Definition of illegal. : not according to or authorized by law : unlawful, illicit; also : not sanctioned by official rules (as of a game)
antibiotic. n. 1. (Pharmacology) 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. adj.
Introduction: An antibiotic is a chemical produced by a fungus or a bacteria that has the potential to limit the growth of another bacteria. Antiseptics are chemicals produced by humans that are used to prevent the growth of bacteria or fungi on living tissues (disinfectants prevent growth on inanimate objects).