e-com·merce (??k?m??rs)n. Commerce that is transacted electronically, as over the internet.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.e-commerce (?i??k?m??s) or ecommercen (Commerce) business transactions conducted on the internet[C20: from e-2 + commerce]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014e-com?merce (?i?k?m ?rs) n. business that is transacted by transferring data electronically, esp. on the Internet. [1995?2000] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.