قَوۡسَیۡنۡ

[1] قَاسَ الشَّىْءَ بِغَيْرهِ , and عَلَى غَيْرِهِ, aor. يَقُوسُهُ, inf. n. قَوْسٌ (S, K *) and قِيَاسٌ, (S,) i. q. قَاسَهُ, aor. يَقِيسُهُ, inf. n. قَيْسٌ (S, K *) and قِيَاسٌ; (S;) i. e., He measured the thing by another thing like it; [both in the proper sense and mentally; but the latter verb is the more common, though the former, accord. to the JK, is the original;] (S, TA;) and so اقتاس ↓ الشَّىْءَ بِغَيْرِهِ: (S, K: *) but you should not say ↓ أَقَسْتُهُ for قُسْتُهُ or قِسْتُهُ. (S.) ＝ 1-A2- قَوِسَ: see 5.