Noun

1. Any of a class of natural and synthetic antibiotics developed from Cephalosporium fungi, having a cepham structure.
   • 2001: Another important group of antibiotics, the cephalosporins, a class that includes more than twenty-five different drugs, are chemically distinct from the penicillins but act in the same way as cell wall inhibitors, as do vancomycin and bacitracin. — Leslie Iversen, Drugs: A Very Short Introduction (Oxford 2001, p. 63)