nam·ay·cush (n?m??-k?sh?, n?m??-)n. See lake trout.[Cree namekos.]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.namaycush (?næm??k??) n (Fishing) a North American freshwater fish (Salvelinus namaycush). Also called: lake trout Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014