Definition of metabisulphite in English:

metabisulphite

Pronunciation /ˌmɛtəbʌɪˈsʌlfʌɪt/

noun

(US metabisulfite)
  • The anion S₂ O₅ 2−; a salt containing this, frequently used as a sterilizing agent or preservative.

Origin

Early 20th century; earliest use found in Proceedings of the Royal Society of London.