موس1 مَاسَ, aor. ـُ (Msb,) inf. n. مَوْسٌ, (Sgh, Msb, K,) He shaved (Sgh, Msb, K) the head, (Sgh, Msb,) or the hair: (K:) but Sgh says, that its correctness requires consideration, and it was doubted by IF. (TA.) See مُوسَى, below.المَاسُ, not أَلْمَاسٌ, (K,) i. e., with the disjunctive hemzeh, (TA,) for this is an incorrect pronunciation, (K,) of the vulgar, as Sgh and others have plainly asserted; but IAth says, I think that the hemzeh and lám in it are radical letters, as they are in الياس, [i. e., إِلْيَاس or أَلْيَاس,] and it is not Arabic; and if so, its place is under the letter hemzeh, because they say أَلْمَاسٌ; but if they be [prefixed] for the purpose of rendering the word determinate, the present is its [proper] place; (TA;) [The diamond;] a certain precious stone, (K, * TA,) reckoned among jewels, like the يَاقُوت and the زُمُرُّرذ, (TA,) the largest of which is like the walnut, (K, TA,) or the egg of the pigeon, (TA,) and this is rare, or very rare, (K, TA,) the only instance being said to be the one called الكَوْكَبُ الدُّرِّىُّ, which is suspended at the tomb of the Prophet: (TA:) it breaks all stony bodies, and the holding it in the mouth breaks the teeth, and fire has no effect upon it, nor iron, but only lead breaks it and powders it, [a strange mistake, for it is well known that it is powdered by being pounded in a steel mortar,] after which it is taken [in the state of powder] upon drills, and pearls &c. are drilled with it. (K.) مُوسَى [A razor;] a certain instrument of iron, (M, Msb, TA,) with which one shaves: (Lth, L, K, TA:) of the measure فُعْلَى, (Ks, M, Msb, K,) from المَوْسُ, [inf. n. of مَاسَ,] so that the م is a radical letter, (K,) accord. to Lth, (TA,) [for] Lth says, (L, TA,) المَوْسُ is the root (تَأْسِيس [lit. foundation]) of المُوسَى, (L, K, TA,) the thing with which one shaves; (L, TA;) therefore, (Az, Msb, K,) it is imperfectly decl., because of the short fem. ا [written ى], (Msb,) without tenween; (Az, K;) and Fr cites a verse [of obscene meaning] in which it is made fem.: (TA:) or it is from أَوْسَيْتُ رَأْسَهُ, meaning “ I shaved his head,” (ISk, M, * Msb, K,) of the measure مُفْعَلٌ, (ISk, Msb, TA,) so that the ى is a radical letter, as El-Umawee and Yz say, and Aboo-'Amr Ibn-el-Alà inclined to think it so, (TA,) and therefore it is perfectly decl., (Msb,) with tenween, (Msb, K,) when  indeterminate; (Msb;) or it is of the measure مُفْعَلٌ because this measure is more common than فُعْلَى, and because it is perfectly decl. when  indeterminate, whereas فُعْلَى is not so when indeterminate and when determinate: (Ibn-EsSarráj, TA:) but IAmb says, that it is masc. and fem., and perfectly decl. and imperfectly decl.: ISk says, that the approved way is to make it perfectly decl.: (Msb:) [but] he says that it is fem. [also, and if so it is imperfectly decl.]: (TA:) and it is related of A'Obeyd, in the Bári', that he said he had not heard it made masc. except by El-Umawee; (Msb;) who  asserted it to be masc. only: (TA:) the pl., accord. to him who makes it imperfectly decl., is مُوسَيَاتٌ; and accord. to him who makes it perfectly decl., مَوَاسٍ. (Msb.) The dim. of موسى, in the sense above explained, [not as a proper name, in which case it is مُوسَى only, without tenween, and has no relation to the same word signifying a razor,] is مُوَيْسِيَةٌ, [but by rule it should be مُوَيْسَى, like حُبَيْلَى,] accord. to him who says هٰذِهِ مُوسَى; and مُوَيْسٍ accord. to him who says هٰذَا مُوسًى. (ISk, TA.)