انقاص, said of sand, (A, Ḳ,) and of dust, or earth, (Ḳ,) It poured forth, or down: (Ḳ:) or it fell, fell down, or collapsed; and so when said of a building; (A;) and so انقاصت said of a well (بِئْر); (Ṣ, A, Ḳ;) it fell; fell down; fell in ruins, or to pieces; or collapsed; (Ṣ, A, Ḳ;) as also انقاضت, with ض; (TA;) andتقيّصت↓: (A, Ḳ:) which↓ last also signifies it (a well) inclined, and became demolished, or fell in ruins; and in like manner [تقيّص said of] a wall. (TA.)

انقاصت السِّنُّ The tooth became broken: (A:) or became cracked, or split, lengthwise: (TA:) or fell out: (Lth, Ḳ:) andقَاصَتْ↓, (TA,) inf. n. قَيْصٌ, (Ṣ, Ḳ,) it fell out from its root; (Ṣ, Ḳ, TA;) and so with ض: (Ṣ, TA:) and انقاص الضِّرْسُ, andقَاصَ↓, andتقّيص↓, the tooth became cracked lengthwise, and fell out. (TA.)

انقاص المَآءُ فِى البِئْرِ The water became abundant in the well (Ḳ, TA) so that it nearly demolished it. (TA.)

بِئْرٌ قَيَّاصَةٌ A well that has collapsed. (A.) And بِئْرٌ قَيَّاصَةُ الجُولِ A well having its wall, or casing, or sides, demolished. (Ibn-ʼAbbád, Ḳ.)

مُنْقَاصٌ signifies Uprooted; (Ṣ, Ḳ;) and مُنْقَاضٌ, with the pointed ض, cracked or split, lengthwise; so says Aṣ.: but AA says, that both signify the same. (Ṣ, O.)