'adjutancy' originates from Latin, specifically the word 'adiutantia,' where 'adiutare' meant 'to help or assist.'

'adiutantia' transformed into the French word 'adjutance,' and eventually became the modern English word 'adjutancy' through Middle English.

Initially, it meant 'to assist or help,' but over time it evolved into its current meaning of 'the position or office of an adjutant.'