Rejuvenate originated as a combination of the prefix re-, which means "again," with the Latin parent of juvenile and junior—juvenis, meaning "young." Rejuvenate literally means "to make young again" and can imply a restoration of physical or mental strength or a return to a more youthful, healthy condition. Things that are timeworn can also be rejuvenated.

Juvenis, Latin for "young", can be seen in a word such as juvenile. Rejuvenation is something that can be carried out on a creaky old house, a clunker of a car, a sluggish career, a weak economy, or a company that's lost its edge, but rejuvenate and rejuvenation are probably used most often for talking about our physical selves. Ads for lotions promise skin rejuvenation; diet-book covers show rejuvenated (or maybe just young) models bursting with health. We still seem to be searching for that "Fuente de la Juventud" that Juan Ponce de León failed to discover five hundred years ago.