ثنى

ثُنَائِىٌّ ذ [a rel. n. from اِثْنَانِ, anomalously formed, but analogous with other rel. ns. from ns. of number, as رُبَاعِىٌّ ثُلَاثِىٌّ, &c., Of, or relating to, two things ]. ― -b2- كَلِمَةٌ ثُنَائِيَّةٌ A word comprising, or composed of, two letters; as يَدٌ, and دُمْ [or دَمٌ?]. (TA.)