'trajectory' originates from Latin, specifically the word 'trajectoria,' where 'tra-' meant 'across' and 'jacere' meant 'to throw.'

'trajectoria' transformed into the French word 'trajectoire,' and eventually became the modern English word 'trajectory' through Middle English.

Initially, it meant 'the act of throwing across,' but over time it evolved into its current meaning of 'the path followed by a projectile.'