اِسْمُ الْمُبَالَغَةِ

Adjectives of the form فَعِيْلٌ and particularly فَعُوْلٌ often indicate either a very high degree of the quality which their subject possesses, or an act which is done extensively or intensively by their subjects and hence they are called intensive forms / أَبْنِيَةُ المُبَالَغَةِ

From verbal adjectives of the form فَاعِلٌ as well as from some others, is derived an adjective فَعَّالٌ which adds intensiveness or habit to the basic meaning hence it is called the noun of intensiveness / اِسْمُ المُبَالَغَةِ 

Other intensive adjectives less common than فَعَّالٌ are فُعَّالٌ and فِعِّيْلٌ and فَعُّوْلٌ and فُعُّوْلٌ and فُعَّلٌ and فَاعُوْلٌ