المعنى الاصطلاحي

Prevalence of doubt and its frequent influence on a person while performing acts of worship.

الشرح المختصر

The scholars of the Maaliki school of Fiqh were the only ones who used the term "istinkaah" (prevalent doubt) to refer to the prevalence of doubt. They mentioned that frequent doubt (regarding the sound performance of the acts of worship) is among the afflictions and trials that befall a person and that its cure is to ignore it. The criterion in deciding whether prevalent doubt amounts to "istinkaah" or not in their school is that it occurs quite often, occurs every time a person makes ablution, in every prayer, or once or twice a day. However, if the person experiences such doubt every other day or every two days, then it is not called "istinkaah". The rest of the scholars - other than the Maalikis - referred to this condition as prevalent or frequent doubt.

التعريف اللغوي المختصر

"Istinkaah": prevalence and intermixing.