col·lu·vi·um (k?-lo?o?v?-?m)n. pl. col·lu·vi·ums or col·lu·vi·a (-v?-?) A loose deposit of rock debris accumulated through the action of gravity at the base of a cliff or slope.[Latin, a collection of washings, dregs, from colluere, to wash thoroughly : com-, intensive pref.; see com- + -luere, to wash; see leu(?)- in Indo-European roots.]col·lu?vi·al adj.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.colluvium (k??lu?v??m) n, pl -via (-v??) or -viums (Geological Science) a mixture of rock fragments from the bases of cliffs[Latin: collection of filth, from colluere to wash thoroughly, from com- (intensive) + luere to wash] col?luvial adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014col?lu?vi?um (k??lu vi ?m) n., pl. -vi?a (-vi ?) -vi?ums. loose earth material that has accumulated at the base of a slope; talus. [1935?40;