'azosulphonic' originates from the combining form 'azo-' (from French 'azo', ultimately from Greek 'azōtos', meaning 'without life' and used in chemistry to denote nitrogen-containing groups) combined with 'sulphonic' from New Latin 'sulphonicus' based on Latin 'sulphur' ('sulfur').

'azo-' was coined in the early 19th century by chemists to name nitrogen-containing compounds; it was later combined with 'sulphonic' (an older British spelling using 'ph') to describe compounds bearing both azo and sulfonic acid groups. In American usage the spelling often shifted to 'sulfonic', giving the alternate form 'azosulfonic'.

Initially, the term denoted simply the presence of both an azo group and a sulfonic acid/sulfonate group; over time it has remained a technical descriptor, chiefly applied to azo dyes and related organic compounds, with little change in core meaning.