methicillin
UK[ˌmɛθɪˈsɪlɪn]US[ˌmɛθəˈsɪlɪn]
n
A semisynthetic penicillin antibiotic that is resistant to penicillinase, used chiefly against staphylococcal infections.
Morpheme Breakdown
meth
i
cillin
meth
chemical group
i
cillin
penicillin derivative
Etymology
The name 'methicillin' is a constructed term from 20th-century scientific nomenclature, designed to describe its chemical relationship to penicillin. The 'meth-' prefix specifies the addition of a methyl group to the core penicillin structure, a modification that made it resistant to the enzyme penicillinase. The '-cillin' suffix anchors it firmly within the family of beta-lactam antibiotics derived from the Penicillium fungus. Thus, the word's logic is chemically literal, directly encoding its status as a methylated penicillin variant developed to overcome bacterial resistance.
Analysis
Structure: meth (chemical group) + i + cillin (penicillin derivative)
- meth: A morpheme derived from "methyl," indicating the presence of a methyl group (CH₃-). Origin: International Scientific Vocabulary, from Greek methy (wine) via German methyl.
- i: A connecting vowel, common in chemical nomenclature.
- cillin: A suffix denoting a compound belonging to the penicillin class of antibiotics. Origin: A truncation of "penicillin," itself from the Latin-derived name of the mold Penicillium.
Examples
Methicillin was once a first-line treatment for serious staphylococcal infections.
The emergence of methicillin-resistant *Staphylococcus aureus* (MRSA) has rendered this antibiotic ineffective for many cases.
The chemical structure of methicillin differs from penicillin by the addition of methoxy groups.