'unexpecting' originates from the prefix 'un-' meaning 'not' and the word 'expect,' which comes from Latin 'expectare,' meaning 'to look out for.'

'expectare' transformed into the Old French word 'expecter,' and eventually became the modern English word 'expect' through Middle English.

Initially, it meant 'to look out for something,' but over time it evolved into its current meaning of 'anticipating or waiting for something.'