'pain-related' originates from the combination of 'pain' and the suffix '-related', where 'pain' refers to physical suffering or discomfort, and '-related' indicates a connection or association.

'pain' comes from Old French 'peine', from Latin 'poena' meaning 'penalty, punishment', and '-related' is derived from the verb 'relate', which comes from Latin 'relatus', the past participle of 'referre' meaning 'to bring back'.

Initially, 'pain' meant 'penalty or punishment', but over time it evolved to mean 'physical suffering or discomfort'.