To prise is to extract or move something using force, the way you'd prise your stolen diary out of your snooping sibling's hands.
The verb prise is good for when you use an effortful physical force. If you're struggling to open an old window that's painted shut, you may need a screwdriver to prise it open. Don't mistake prise for its homonym prize, which as a verb means "to cherish or appreciate." The two words do share a root, the Latin prendere, "to grasp, seize, or catch."