'investigation' originates from Latin, specifically the word 'investigatio', where 'in-' meant 'into' and 'vestigare' meant 'to track or trace'.

'investigatio' transformed into the Old French word 'investigacion', and eventually became the modern English word 'investigation'.

Initially, it meant 'the act of tracking or tracing', but over time it evolved into its current meaning of 'detailed examination'.