'nonirritating' originates from English, specifically the prefix 'non-' plus the present participle 'irritating', where 'non-' meant 'not' and 'irritating' derives from 'irritate' meaning 'to provoke or excite'.

'irritate' comes from Latin 'irritare' meaning 'to excite or provoke'; it entered English via Old French or Medieval Latin as 'irritare/irritare' and became the modern English verb 'irritate', whose present participle is 'irritating'; the prefix 'non-' was later attached to form 'nonirritating'.

Initially, 'irritate' meant 'to excite or provoke'; over time it came to mean 'to cause annoyance or inflammation', and 'nonirritating' evolved to mean 'not causing such irritation'.