A person is “drunk” when he is so far under the influence of liquor that his passions are visibly excited or his judgment impaired, or when his brain is so far affected by potations of liquor that his intelligence, sense-perceptions, judgment continuity of thought or of ideas, speech, and coordination of volition with muscular action (or some of these faculties or processes) are impaired or not under normal control.
DRUNK
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.