nitrite

noun

1. Any salt or ester of nitrous acid.

   “John Birdsall, a scientist for the American Meat Institute, said that there were no industry qualms about trying to lower the nitrite amounts even farther. For centuries, some form of nitrites have been used to cure and to preserve bacon and to give it a pink color.”

2. The univalent radical -NO₂, and the anion NO₂⁻