ac·a·ri·a·sis (?k??-r???-s?s)n. Infestation with or disease caused by mites or ticks.[acar(id) + -iasis.]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.acariasis (?æk??ra??s?s) n (Pathology) infestation of the hair follicles and skin with acarids, esp mites[C19: New Latin. See acarus, -iasis]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ac?a?ri?a?sis (?æk ??ra? ? s?s) n. pl. -ses (-?siz) 1. infestation with acarids, esp. mites. 2. a skin disease caused by such infestation, as scabies. [1820?30] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.acariasisthe condition of being infested by acarids or mites.See also: Infestation-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.