The story
From methy(l) + -cillin (“6-aminopenicillanic acid derivative”).
Etymology from Wiktionary, CC BY-SA 4.0.
meticillin
Today it means: A semisynthetic form of penicillin C₁₇H₂₀N₂O₆S used especially in the form of its sodium salt against staphylococci which produce penicillinase. Full definition →