IPA: //sʌlˈfɒnɪl//
KK: /sʌlˈfɔːnɪl/
A chemical group consisting of a sulfur atom bonded to two oxygen atoms, often found in various chemical compounds.
The sulfonyl group is important in the synthesis of many pharmaceuticals.
Sulfonyl is formed from "sulfur" (from Latin *sulfur*, meaning sulfur) and "-onyl" (a suffix used in chemistry to denote a functional group). The word refers to a functional group containing sulfur, typically bonded to oxygen and carbon.
Think of 'sulfur' as the key element in 'sulfonyl', which helps you remember that this term relates to a specific chemical group involving sulfur.