The story
From the legal case Terry v. Ohio, 392 U.S. 1 (1968), in which the Supreme Court held that police may briefly detain a person who they reasonably suspect is involved in criminal activity.
Etymology from Wiktionary, CC BY-SA 4.0.
Terry stop
Today it means: The brief detention of a person by the police on reasonable suspicion of involvement in criminal activity but short of probable cause to arrest. Full definition →