'conventionally-expressed' originates from the Latin word 'conventio,' meaning 'agreement,' and the Latin word 'expressus,' meaning 'pressed out.'

'conventio' transformed into the Old French word 'convention,' and 'expressus' became the Middle English word 'express,' eventually forming the modern English term 'conventionally-expressed.'

Initially, it meant 'expressed according to an agreement,' but over time it evolved into its current meaning of 'expressed in a traditional manner.'