under the influence - Legal Definition
Webster's New World Law Dictionary Copyright © 2010 by Wiley Publishing, Inc., Hoboken, New Jersey. Used by arrangement with John Wiley & Sons, Inc.
See driving while intoxicated.
under the influence - Phrases/Idioms
Impaired functioning owing to alcohol consumption, as in He was accused of driving under the influence. This expression, from legal jargon, is short for under the influence of intoxicating liquor and implies that one is not completely drunk. Since it is nearly always applied to drivers suspected or so accused, it has given rise to the police acronym DUI, for “driving under the influence.” [Second half of 1800s]