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.
An antimicrobial is a type of drug that kills or stops the growth of microbes, such as bacteria, viruses, fungi, and parasites.Antibiotic resistance is the ability of bacteria to resist the effects of an antibiotic â that is, the bacteria are not killed, and their growth is not stopped.n antimicrobial is a type of drug that kills or stops the growth of microbes, such as bacteria, viruses, fungi, and parasites.