sodium bisulfite

noun

variants or less commonly sodium acid sulfite

: either of two salts usually obtained by passing sulfur dioxide through a solution of sodium carbonate:

a

: an unstable crystalline salt NaHSO₃ that is known especially in solution and forms sodium metabisulfite on dehydration; sodium hydrogen sulfite

b

: sodium metabisulfite

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!