horizontal gaze nystagmus test
horizontal-gaze nystagmus test. Criminal law. A field-sobriety test for intoxication, in which the suspect is told to focus on an object (such as a pencil) and to track its movement, usu. from side to side, by moving only the eyes. • Intoxication is indicated if the eyes jerk or twitch while tracking the object. — Abbr. HGN test. [Cases: Automobiles 411. C.J.S. Motor Vehicles §§ 1397–1411.]
