Precaution. 

Iḥtiyāṭ can be either obligatory (Iḥtiyāṭ wajib) or recommended (Iḥtiyāṭ mustahab). In the school of fiqh (Islamic law), jurists may require or recommend acts of caution in certain areas.

For example, when fasting it is a precaution to stop eating and drinking approximately ten minutes prior to the time of fajr (
imsaak),  in case the estimation for the time of fajr is incorrect.