'abnormal' originates from Latin, specifically the word 'abnormis,' where 'ab-' meant 'away from' and 'norma' meant 'rule or pattern.'

'abnormis' transformed into the French word 'anormal,' and eventually became the modern English word 'abnormal' through Middle English.

Initially, it meant 'away from the norm or rule,' and this meaning has largely remained the same in modern usage.