I. ˈsəl-fə-ˌnāt noun
Date: 1876
: a salt or ester of a sulfonic acid
II. transitive verb
( -nat·ed ; -nat·ing )
Date: 1882
: to introduce the SO 3 H group into ; broadly : to treat (an organic substance) with sulfuric acid
• sul·fo·na·tion ˌsəl-fə-ˈnā-shən noun