'conventionally-made' originates from 'convention,' specifically the word 'conventio' in Latin, where 'con-' meant 'together' and 'venire' meant 'to come.'

'conventio' transformed into the Old French word 'convention,' and eventually became the modern English word 'convention' through Middle English.

Initially, it meant 'a coming together or agreement,' but over time it evolved into its current meaning of 'produced following traditional methods.'