'intermediary' originates from Latin, specifically the word 'intermedius,' where 'inter-' meant 'between' and 'medius' meant 'middle.'

'intermedius' transformed into the French word 'intermédiaire,' and eventually became the modern English word 'intermediary' through Middle English.

Initially, it meant 'being in the middle,' but over time it evolved into its current meaning of 'acting as a mediator or agent.'