in·ter se (?n?t?r s??, s??)adv. & adj. Between or among themselves.[Latin inter s? : inter, between + s?, themselves.]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.inter se (??nt? ?se?) adv (Literary & Literary Critical Terms) among or between themselvesCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014