Main Entry: ox·a·cil·lin Pronunciation: "äk-s&-'sil-&n Function: noun : a semisynthetic penicillin administered in the formof its hydrated sodium salt C19H18N3NaO5S·H2O to treat infections caused by penicillin-resistant staphylococci
oxacillin ox·a·cil·lin (ŏk'sə-sĭl'ĭn) n. A semisynthetic penicillin effective against penicillin-resistant infections, especially those of staphylococci.