soft brick

When a phone or other electronic device is rendered entirely unusable ("bricked", ie, the device has the functionality of a brick), but in a non-permanent way, such that with the correct tools and techniques, it can be revived. Contrast with "hard brick" where the device is well and truly useless. The process of unbricking it may still be enough work that one may choose to just get a new one (depending on how expensive it is to replace).

Generally implies that the damage is done to the firmware or software, not the hardware - a phone that was dunked in a fishtank might well be destroyed, but one wouldn't call that "bricked"

Your phone becomes nearly impossible to use, slower, less functional, and is usually because of a virus or various malware.