الف

أَلْفٌ ذ , meaning A certain number, (S, M, K,) well known, (M,) i. e. a certain round number, (Msb,) [namely a thousand, ] is of the masc. gender: (T, S, Msb, K:) you say ثَلَاثَةُ اآلَافٍ [ Three thousand ], not ثَلَاثَ اآلَافٍ; (TA;) and هٰذَا أَلْفٌ وَاحِدٌ [ This is one thousand ], not وَاحِدَةٌ; (S;) and أَلْفٌ أَقْرَعُ, [ A complete thousand ], (T, S,) not قَرْعَاآءُ: (S:) it is not allowable to make it fem.: so say IAmb and others: (Msb:) or it is allowable to make it fem. as being a pl.: (T:) or, accord. to ISK, it is allowable to say, هٰذِهِ أَلْفٌ as meaning هٰذِهِ الدَّرَاهِمُ أَلْفٌ [ These dirhems are a thousand ]; (S, K; *) and Fr and Zj say the like: (Msb:) the pl. is اآلُفٌ, applied to three, (M,) and اآلَافٌ, (T, S, M, Msb, K,) applied to a number from three to ten, inclusively, (TA,) and أُلُوفٌ, (T, S, M, Msb, K,) used to denote more than ten; (T;) and الأَافُ [in the TA الأَلَفُ] is used by poetic licence for الاآلَافُ, by suppression of the [radical] ل (M.)