عَدْنٍ

A word in the Arabic language will either be 1) a verb or 2) a noun or 3) a particle – عَدْنٍ is a noun

A noun may either be 1) Definite or indefinite 2) Masculine or feminine 3) Singular, dual or plural 4) Nominative, accusative or genitive

عَدْنٌ is the natural state of this indefinite noun and it becomes عَدْنٍ due to: 1) a preposition that precedes it or 2) a possessed noun that precedes it or 3) it’s a noun of dependent declension a) نَعْتٌ / صِفَطٌ adjectives b) التَّوْكِيْدُ emphatic c) المَعْطُوْفٌ conjunction d) البَدَلُ synonym

Everlasting, Perpetual abode, Eternity

To abide constantly, stay in (a place), remain, everlasting

Surah/Below are the 11 verses in the holy Quran containing the genitive nounعَدْنٍ
Verse
Allah (SWT) promised the believers men and women gardens (paradise), flows from underneath itوَعَدَ اللهُ المُؤْمِنِيْنَ وَالمُؤْمِنَاتِ جَنَّاتٍ تَجْرِي مِنْ تَحْتِهَا
rivers, abiding therein forever, and blessed dwellings in gardens of eternityالأَنْهَارُ خَالِدِيْنَ فِيْهَا وَمَسَاكِنَ طَيِّبَةً فِي جَنَّاتِ عَدْنٍ
9-72but the approval of Allah (SWT) is greater, that, it is the great successوَرِضْوَانٌ مِّنَ اللهِ أَكْبَرُ ذَلِكَ هُوَ الفَوْزُ العَظِيْمُ
13-23
16-31
18-31
19-61
20-76
35-33
38-50
40-8
61-12
Their reward is with their Lord, gardens of eternity, underneath which rivers flow, they will abideجَزَاؤُهُمْ عِنْدَ رَبِّهَمْ جَنَّاتُ عَدْنٍ تَجْرِي مِنْ تَحْتِهَا الأَنْهَارُ خَالِدِيْنَ فِيْهَا أَبَدًا
98-8therein forever, Allah SWT pleased with them and they with Him, that is for who feared his Lordرَضِيَ اللهُ عَنْهُمْ وَرَضُوْا عَنْهُ ذَلِكَ لِمَنْ خَشِيَ رَبَّهُ