'undetected' originates from the prefix 'un-' meaning 'not' and the verb 'detect' from Latin 'detegere', where 'de-' meant 'away' and 'tegere' meant 'to cover'.

'detegere' transformed into the Old French word 'detec(t)er', and eventually became the modern English word 'detect' through Middle English.

Initially, 'detect' meant 'to uncover or reveal', and over time it evolved into its current meaning of 'discover or notice'.