'optimism' originates from Latin, specifically the word 'optimus,' where 'optimus' meant 'best.'

'optimus' transformed into the French word 'optimisme,' and eventually became the modern English word 'optimism' through Middle English.

Initially, it meant 'the doctrine that this world is the best of all possible worlds,' but over time it evolved into its current meaning of 'a general disposition to expect the best in all things.'