os·tler (?s?l?r)n. Variant of hostler.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.ostler (??sl?) or hostlern (Horse Training, Riding & Manège) archaic a stableman, esp one at an inn[C15: variant of hostler, from hostel]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014hos?tler (?h?s l?r, ??s l?r) n. 1. a person who takes care of horses, esp. at an inn. 2. a person who services trains, buses, etc., or maintains large machines. [1350?1400; Middle English; variant of hosteler] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.ostler – A stableman at an inn.See also related terms for inn.Farlex Trivia Dictionary. © 2012 Farlex, Inc. All rights reserved.