ک د رk-d-r
(ن) كَدَرَ يَكْدُرُ كُدُوْرَةًkadara yakduru kudūratan: to be dirty and turbid — the opposite of صَفَاءṣafāʾ. (This verb is not used in the Quran.)
Form VII (infiʿāl) اِنْكَدَرَ يَنْكَدِرُ اِنْكِدَارًاinkadara yankadiru inkidāran: to fall off, to fall scattered, to lose one's light. Only once in the Quran, in the scenes of the Resurrection: ﴿وَإِذَا النُّجُوْمُ انْكَدَرَتْ﴾ (At-Takwīr 81:2).