Where does “นายพลเอก” come from?

นายพลเอก (Thai) comes from Thai เอก, from Pali eka, from Sanskrit एक, from Proto-Indo-Aryan Háykas, from Proto-Indo-Iranian Háykas, from Proto-Indo-European óynos — one; single.

Ancestry of “นายพลเอก”, step by step

StepLanguageWordMeaning
1Thaiเอกsole; single; solitary; one; alone; lonely;...
2Paliekaone
3Sanskritएकone; alone, solitary, single, happening only...
4Proto-Indo-AryanHáykasone
5Proto-Indo-IranianHáykasone
6Proto-Indo-Europeanóynosone; single
Every word from Proto-Indo-European óynos →Every word from Proto-Indo-Iranian Háykas →Every word from Proto-Indo-Aryan Háykas →