'prone' originates from Latin, specifically the word 'pronus,' where 'pro-' meant 'forward' and 'nus' meant 'inclined.'

'pronus' transformed into the Old French word 'prone,' and eventually became the modern English word 'prone' through Middle English.

Initially, it meant 'inclined forward,' but over time it evolved into its current meanings of 'likely to experience something' and 'lying flat.'