one-armed bandit (w?n?ärmd?)n. A slot machine for gambling operated by pulling a lever on the side.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.one-armed bandit or one-arm banditn (Gambling, except Cards) a fruit machine operated by pulling down a lever at one sideCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014slot? machine` n. 1. a gambling machine operated by inserting coins into a slot and pulling down a long handle attached to its side. 2. any machine operated by inserting coins into a slot, as a vending machine. [1890?95] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.