Definition of methacholine in US English:

methacholine

noun

Pharmacology
  • A choline derivative with parasympathomimetic activity that can induce bronchoconstriction in asthmatics and is used in tests of airway responsiveness; O-acetyl-β-methylcholine, C₈H₁₈ClNO₂.

Origin

1940s; earliest use found in Science. From meth- (in methyl: see note s.v. meth-) + -a- connective + choline.

Pronunciation

methacholine

/mɛθəˈkəʊliːn/