nafcillin
nounUS /næfˈsɪl.ɪn/
Etymology From naph(thalene) + -cillin (“6-aminopenicillanic acid derivative”).
1
Medicine, Pharmacology, Sciences A semisynthetic penicillin that is resistant to beta-lactamase and is used especially in the form of its hydrated sodium salt C₂₁H₂₁N₂NaO₅S·H₂O as an antibiotic.