العَقَبَةُ

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

العَقَبَةُ is the natural state of a definite noun and it is in this state ( مَرْفُوْعٌ) when the noun is: 1) the subject المُبْتَدَأُ or 2) the predicate الخَبَرُ or 3) اسْمُ كَانَ or 4) خَبَرُ إِنَّ or 5) الفَاعِلُ subject of a verb in the active voice or 6) نَائِبُ الفَاعِلِ subject of a verb in the passive voice or 7) it’s a noun of dependent declension a) نَعْتٌ / صِفَطٌ adjectives b) التَّوْكِيْدُ emphatic c) المَعْطُوْفٌ conjunction d) البَدَلُ synonym

Steep and difficult ascent; Mountain road; Road in the upper part of a mountain or a long mountain that lies across the way; Difficult affair and path of duty

To succeed, take the place of, come after, strike on the heel, come at the heel, follow anyone closely

مَعْرِفَةٌمُفْرَدٌمُؤَنَّثٌمَرْفُوْعٌع ق ببَاب نَصَرَفَعَلَةٌعَقَبَ يَعْقُبُاسْمٌاِسْمُ الجِنْسِ
DefiniteSingularFeminineNominativeRootThe steep pathPatternنNounGeneric or common Noun
Surah/Below is the only verse in the holy Quran containing the definite nounالعَقَبَةُ
Verse
90-12and what will make you know the path that is steep?وَمَآ أَدْرَاكَ مَا العَقَبَةُ