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.
Dr. Sayeed Ahmad D. I. Hom. (London) Antibiotic is a substance produced by certain bacteria or fungi that kills other cells or interferes with their growth.In nature, these substances help some microbes survive by limiting the multiplication of other microbes that share the same environment.r. Sayeed Ahmad D. I. Hom. (London) Antibiotic is a substance produced by certain bacteria or fungi that kills other cells or interferes with their growth.