أَثْقَالَ

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

الأَثْقَالُ is the natural state of this definite noun and becomes الأَثْقَالَ due to it being the: 1) المَفْعُوْلُ بِهِ object of a verb or 2) اسْمُ of إِنَّ or 3) خَبَرُ of كَانَ or 4) المَفْعُوْلُ فِيْهِ adverb of time or place or 5) المَفْعُوْلُ لَهُ noun that gives the reason for doing a thing or 6) المَفْعُوْلُ مَعَهُ noun that comes after the و which means “along with” or 7) المَفْعُوْلُ المُطْلَقُ is the مَصْدَرٌ of the verb occurring in the sentence or 8) الحَالُ adverb of manner or 9) التَّمْيِيْزُ noun that specifies the meaning of a vague word or 10) المُسْتَثْنَى noun that comes after إِلَّا meaning “except” or 11) المُنَادَى noun of calling or 12) it’s a noun of dependent declension a) نَعْتٌ / صِفَطٌ adjectives b) التَّوْكِيْدُ emphatic c) المَعْطُوْفٌ conjunction d) البَدَلُ synonym

الأَثْقَالَ loses it’s definite article, becoming أَثْقَالَ due to it being a possessed noun

To be born down heavily, incline heavily downwards

To be heavy, weighty, slow, dull, sluggish, difficult, hard, grievous

Surah/Below are the 3 verses in the holy Quran containing the possessed nounأَثْقَالَ
Verse
16-17
29-13
99-2and the earth throws out its burdensوَأَخْرَجَتِ الأَرْضُ أَثْقَالَهَا