أَلْفٌ

, meaning A certain number, (S, M, K,) well known, (M,) i. e. a certain round number, (Msb,) [namely a thousand,] is of the masculine gender: (T, S, Msb, K:) you say ثَلَاثَةُ الَافٍ [Three thousand], not ثَلَاثَ الَافٍ; (TA;) and هٰذَا أَلْفٌ وَاحِدٌ [This is one thousand], not وَاحِدَةٌ; (S;) and أَلْفٌ أَقْرَعُ, [A complete thousand], (T, S,) not قَرْعَاءُ: (S:) it is not allowable to make it feminine: so say IAmb and others: (Msb:) or it is allowable to make it feminine as being a plural: (T:) or, according 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 plural is الُفٌ, applied to three, (M,) and الَافٌ, (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 الالَافُ, by suppression of the [radical] ل (M.)