phenethicillin
noun
phe·neth·i·cil·lin
| \ fi-ˌneth-ə-ˈsil-ən
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Medical Definition of phenethicillin
: a semisynthetic penicillin administered orally in the form of its potassium salt C17H19KN2O5S and used especially in the treatment of less severe infections caused by bacteria that do not produce beta-lactamase