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.
Antibiotics (From ancient Greek Î±Î½ÏÎ¹Î²Î¹Î¿ÏÎ¹ÎºÎ¬, antiviotika) also called antibacterials, are a type of antimicrobial[1] drug used in the treatment and prevention of bacterial infections.[2][3] They may either kill or inhibit the growth of bacteria.