ត្រីសព្ទ (Khmer) comes from Khmer ត្រី, from Sanskrit त्रि, from Proto-Indo-Aryan tráyas, from Proto-Indo-Iranian tráyas, from Proto-Indo-European *tréyes.
Ancestry of “ត្រីសព្ទ”, step by step
ត្រីសព្ទ traces back through two separate lines of ancestry.