ain (?n)adj. Scots Own.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.ain (e?n) determiner a Scot word for ownain (???j?n) n (Letters of the Alphabet (Foreign)) a variant of ayinAin (French ??) n1. (Placename) a department in E central France, in Rhône-Alpes region. Capital: Bourg. Pop: 539 006 (2003 est). Area: 5785 sq km (2256 sq miles)2. (Placename) a river in E France, rising in the Jura Mountains and flowing south to the Rhône. Length: 190 km (118 miles)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ain (e?n) adj. Scot. own. [1700?25; representing Old English ?gen or Old Norse eiginn] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.