The grammatical category of a word according to its position or function in the sentence. Arabic exhibits three cases:

1. the nominative case is called الرفع  (al-raf‘) and the noun/adjective/verb in the case is called ٱلْمَرْفُوعُ  (al-marfū‘),

2. the accusative case is called النصب  (an-naṣb) and the noun/adjective/verb in the case is called ٱلْمَنْصُوب  (al-manṣūb)

3. the genitive case is called الجر (al-jarr) and the noun/adjective in the case is called ٱلْمَجْرُورُ  (al-majrūr)

4. the zero-case / sukūn case is called الجزم (al-jazm) and the verb in the case is called ُالْمَجْزُوم  (al-majzūm)

which are reflected in the respective case endings.

For more information see under the respective cases.