| ̷ ̷ ̷ ̷ˌ ̷ ̷+- noun
Etymology: International Scientific Vocabulary nitrosyl + sulfuric
: a crystalline acid NOHSO 4 that is formed by the reaction of nitrogen oxides or fuming nitric acid with sulfuric acid or sulfur dioxide (as in the manufacture of sulfuric acid by the chamber process) and that is used chiefly in the form of a straw-colored corrosive oily liquid containing over half sulfuric acid in making dyes and dye intermediates (as by diazotization); nitrosyl hydrogen sulfate