'opioid' originates from 'opium', specifically the word 'opion', where 'opos' meant 'juice'. 'Associated' comes from Latin, specifically the word 'associatus', where 'ad-' meant 'to' and 'sociatus' meant 'joined'.

'opioid' changed from the Greek word 'opion' and eventually became the modern English word 'opioid'. 'Associated' transformed from the Latin word 'associatus' and eventually became the modern English word 'associated'.

Initially, 'opioid' meant 'related to opium', but over time it evolved into its current meaning of 'related to synthetic or natural substances that act on opioid receptors'. 'Associated' has largely retained its original meaning of 'joined or connected'.