ق ع رq-ʿ-r
(ف) قَعَرَ يَقْعَرُ قَعْرًاqaʿara yaqʿaru qaʿran: to reach the bottom of a thing; to uproot. (This verb is not used in the Quran.)
قَعْرqaʿr: depth, bottom.
Form VII (infiʿāl) اِنْقَعَرَ يَنْقَعِرُ اِنْقِعَارًاinqaʿara yanqaʿiru inqiʿāran: to be uprooted; مُنْقَعِرmunqaʿir (active participle, ism fāʿil). Only once in the Quran, in the fate of the people of ʿĀd: ﴿تَنْزِعُ النَّاسَ كَأَنَّهُمْ أَعْجَازُ نَخْلٍ مُّنْقَعِرٍ﴾ (Al-Qamar 54:20) — that is, uprooted trunks of date-palms.