'juvenescence' originates from Latin, specifically the word 'juvenescere,' where 'juven-' meant 'young' and '-escere' meant 'to begin to be.'

'juvenescere' transformed into the French word 'juvénescence,' and eventually became the modern English word 'juvenescence' through Middle English.

Initially, it meant 'beginning to be young,' but over time it evolved into its current meaning of 'the state of being youthful.'