المعنى الاصطلاحي

Angels who take alternate shifts in protecting man from all directions. However, when he is destined to be stricken by an affliction, they leave him to it.

الشرح المختصر

The "mu‘aqqibāt" (successive guardian angels) are the angels entrusted with the task of protecting man in his residence and travels, when he is asleep and awake, and from all directions. They protect him from all kinds of harm that are not destined to befall him. They watch over him as ordered by Allah, the Almighty. When Allah’s destiny strikes, they do not attempt to protect that person. They are called "mu‘aqqibāt" because they succeed each other; the night guardians succeed the day guardians, and so forth. These angels are different from the angels who write down one's deeds and keep a precise account of whatever one does or says.

التعريف اللغوي المختصر

"Mu‘aqqibāt" (sing. mu‘aqqibah): angels of the night who succeed angels of the day, and angels of the day who succeed angels of the night. It is as if they take on their guard task in turn. Original meaning: delaying something and doing it after something else. "Mu‘aqqib": what follows something else. Other meanings: pronouncing "tasbeeh" (saying: Sobhān Allah [glory to Allah]) one time after another.