Definition of pyridinium in US English:

pyridinium

noun

Chemistry
  • A cation having the formula C₅H₆N+, consisting of a protonated pyridine molecule. Usually attributive or as a formative element in chemical names.

Origin

Late 19th century; earliest use found in Journal of the American Chemical Society. From pyridine + -ium.

Pronunciation

pyridinium

/ˌpɪrɪˈdɪnɪəm/