سينسِينٌ One of the letters of the alphabet: (S, M, L, K:) [i. e., the name of that letter: (see art. س:)] of the masc. gender as being supposed to be a حَرْف [or letter], and fem. as being supposed to be a كَلِمَة [or word]. (L.) The saying فُلَانٌ لَا يَحْسِنُ سِنَهُ means Such a one will not form well one of the three شُعَب [i. e. teeth, or cusps,] of his س. (S, L.) سِينَآءُ Certain stones, (M, L, K,) so says Zj, (M, L,) well-known: (K:) whence the name of a certain mountain in Syria. (M, L.) سِينِيَّةٌ A certain tree; (M, L, K;) mentioned  by AHn on the authority of Akh: (M, L:) pl. سِينِينٌ. (M, L, K.)