'eccentricity' originates from Medieval Latin, specifically the word 'eccentricitas,' where 'ex-' meant 'out of' and 'centrum' meant 'center.'

'eccentricitas' transformed into the French word 'excentricité,' and eventually became the modern English word 'eccentricity' through Middle English.

Initially, it meant 'deviation from a circular path,' but over time it evolved into its current meaning of 'unconventional behavior.'