jaunatne (Latvian) comes from Latvian jauns, from Proto-Balto-Slavic jauˀnás, from Proto-Indo-European h₂yéwHō, from Proto-Indo-European h₂óyu, from Proto-Indo-European h₂ey- — vital force, life, age, eternity; day, morning.
jaunatne (Latvian): youth