zonk (zôngk, z?ngk)v. zonked, zonk·ing, zonks Slang v.tr.1. To cause to be asleep. Often used with out: My roommate was zonked out on the couch.2. To stupefy or intoxicate with drugs or alcohol: “zonk their patients with tranquilizers” (Psychology Today).v.intr.1. To go to sleep or be asleep. Often used with out.2. To become intoxicated with drugs or alcohol.[Origin unknown.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.zonked (z??kt) adj1. (Recreational Drugs) highly intoxicated from drugs or alcohol2. utterly exhausted[C20: of imitative origin]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014zonked (z??kt, z??kt) adj. Slang. 1. stupefied from or as if from alcohol or drugs; high. 2. exhausted or asleep. [1955?60, Amer.] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.