From Aramaic ܬܪܝܢ (tərēn), from Proto-Semitic *ṯināni. Compare Harsusi ثرُه m (ṯruh, “two”).
ܐܶܬ݂ܶܪ (ʾeṯər) m (feminine ܬ݂ܰܪܬ̤ (ṯarč))