Where does “خردسال” come from?

خردسال (Persian) comes from Persian سال, from Middle Persian ŠNT, from Old Persian 𐎰𐎼𐎭, from Proto-Iranian carHdáh, from Proto-Indo-Iranian ćarHáts, from Proto-Indo-European ḱelh₁- — to warm up, to be hot; to warm up, be hot.

خردسال (Persian): minor, underage; youth of tender years

Definitions

minor, underage; youth of tender years

Ancestry of “خردسال”, step by step

خردسال traces back through two separate lines of ancestry.

via Persian سال

Step	Language	Word	Meaning
1	Persian	سال	year
2	Middle Persian	ŠNT	year
3	Old Persian	𐎰𐎼𐎭	year
4	Proto-Iranian	carHdáh	autumn, summer; year
5	Proto-Indo-Iranian	ćarHáts	autumn, summer; year
6	Proto-Indo-European	ḱelh₁-	to warm up, to be hot; to warm up, be hot

via Persian خرد

Step	Language	Word	Meaning
1	Persian	خرد	little, small; insignificant; wisdom, intellect,...
2	Proto-Indo-Iranian	krátuš	intelligence, mental power
3	Proto-Indo-European	krétus	—
4	Proto-Indo-European	kret-	insight, intelligence; strength

Every word from Proto-Indo-European ḱelh₁- →Every word from Proto-Indo-Iranian ćarHáts →Every word from Proto-Iranian carHdáh →