What is Stop And Frisk?

Legal Definition
A brief, non-intrusive, police stop of a suspect. The Fourth Amendment requires that the police have a reasonable suspicion that a crime has been, is being, or is about to be committed before stopping a suspect. If the police reasonably suspect the person is armed and dangerous, they may conduct a frisk, a quick pat-down of the person’s outer clothing. See Terry v Ohio, 392 US 1, (1967).
Legal Definition
Stop and frisk is when police temporarily detain somebody and pats down their outer clothing when there are specific articulable facts leading a reasonable police officer to believe a person is armed and dangerous.