استاِسْتٌ, signifying The podex, or the anus, (K,) or signifying the former, and sometimes used as meaning the latter, (S in art. سته,) is with a conjunctive hemzeh, [written اسْتٌ, when not immediately preceded by a quiescence,] and its final radical letter is clided; for the original form is سَتَهٌ; (Msb;) and it is mentioned in art. سته. (K.) [It is of the fem. gender.] It is said in a prov., applied to him who fails of attaining the object that he seeks, أَخْطَأَتِ اسْتُهُ الحُفْرَةَ [His anus missed the hole in the ground]. (Meyd.) —[Hence,] اِسْتُ الدَّهْرِ (tropical:)  The first, or beginning, of time; (A;) old, or ancient, time. (IB, A, * K. *) One says, مَا زَالَ عَلَى اسْتِ الدَّهْرِ مَجْنُونًا (tropical:)  [He ceased not, or has not ceased, from the beginning of time, or from old time, to be insane, or mad; or] he always was, or always has been, known as being insane, or mad: like as one says, عَلَى إِسِّ الدَّهْرِ. (Az, S.) And Aboo-Nukheyleh says, مَا زَالَ مُذْ كَانَ عَلَى ا سْتِ الدَّهْرِ ذَا حُمُقٍ يَنْمِى وَعَقْلٍ يَحْرشى (tropical:)  [He ceased not, or has not ceased, to be, since he was in the beginning of time, or in old time, i. e., from the first of his existence, a person of increasing foolishness, and of decreasing intellect]. (Az, S.) IB says, J has erred in mentioning است in this section [of the S]; its proper place being in art. سته, where he has also mentioned it; for its hemzeh is conjunctive, by common consent; and if conjunctive, it is augmentative: also, his saying that they have changed the [final]س in إِسٌّ into ت, like as they have changed the [final] س of طَسٌّ into ت, making this word طَسْتٌ, is a mistake; for, were it so, the hemzeh of است would be disjunctive [in every case; whereas it is always conjunctive except after a pause, when it is pronounced with kesr]: moreover, he has attributed this assertion to Az, who never made it, but only mentioned است الدهر with اسّ الدهر because of their agreement in meaning. (TA.) b2:  [Hence also,] اِسْتُ الكَلْبَةِ (assumed tropical:)  Calamity, or misfortune: (K:) adversity; difficulty; distress; affliction: (TA:) what is hated, disliked, disapproved, foul, abominable, or evil. (K.) b3:  and اِسْتُ المَتْنِ (assumed tropical:)  The desert: (K:) or the wide desert. (TA.) b4:  See also art. سته.أُسْتِىٌّ The warp of cloth; (K;) as also أُسْدِىٌّ and أُزْدِىٌّ: (TA:) but it is improperly mentioned in this art.; for it is [originally أُسْتُوىٌ,] of the measure أُفْعُولٌ. (K.) اِسْتِىٌّ Of, or relating to, the اِسْت. (TA in art. سته.)