(ن) دَبَرَ يَدْبُرُ دُبُوْرًاdabara yadburu dubūran: (of a thing) to reach its end, to recede.
دَابِرٌdābir (active participle, ism fāʿil): that which reaches the end; root, last remnant. ﴿فَقُطِعَ دَابِرُ الْقَوْمِ الَّذِيْنَ ظَلَمُوْا﴾ (Al-Anʿām 6:45)
دُبُرٌdubur pl. اَدْبَارٌadbār: the rear or last part of a thing; back. ﴿وَقَدَّتْ قَمِيْصَهُۥ مِنْ دُبُرٍ﴾ (Yūsuf 12:25); ﴿وَلَّوُا الْاَدْبَارَ﴾ (Al-Fatḥ 48:22)
Form IV (ifʿāl) اَدْبَرَ يُدْبِرُ اِدْبَارًاadbara yudbiru idbāran: to turn one's back on someone, to turn away; to be about to end. ﴿وَالَّيْلِ اِذْ اَدْبَرَ﴾ (Al-Muddaththir 74:33)
Form II (tafʿīl) دَبَّرَ يُدَبِّرُ تَدْبِيْرًاdabbara yudabbiru tadbīran: to bring something to its end or outcome, to plan and manage an affair. ﴿يُدَبِّرُ الْاَمْرَ﴾ (Yūnus 10:3)
Form V (tafaʿʿul) تَدَبَّرَ يَتَدَبَّرُ تَدَبُّرًاtadabbara yatadabbaru tadabburan: to try to reach the end or outcome of something, to ponder and reflect. ﴿اَفَلَا يَتَدَبَّرُوْنَ الْقُرْاٰنَ﴾ (An-Nisāʾ 4:82)