'federal' originates from Latin, specifically the word 'foedus,' where 'foedus' meant 'covenant' or 'treaty.'

'foedus' transformed into the French word 'fédéral,' and eventually became the modern English word 'federal' through Middle English.

Initially, it meant 'pertaining to a treaty or agreement,' but over time it evolved into its current meaning of 'relating to a federation or central government.'