l-ghab- with a fatha on the ghayn—[meaning] to experience fatigue (laghaban and lughuban). There is another dialect for it: laghiba with a kasra on the ghayn. And al-lughub means fatigue.
Interpretation of verses 39 to 40 of Surah Q.
بِفَتْح الْغَيْن - لَغَبًا ولُغُوبًا، وَفِيه لُغَة أُخْرَى: لَغِبَ - بِكَسْر الْغَيْن - واللغوب: الإعياء.
تَفْسِير الْآيَات من ٣٩ وَحَتَّى ٤٠ من سُورَة ق.