tin·ni·tus (t?-n??t?s, t?n??-)n. pl. tin·ni·tus·es Noise such as buzzing, ringing, or whistling, heard in the ear without an external stimulus and having multiple causes including infection, trauma, and drugs.[Latin tinn?tus, from past participle of tinn?re, to ring, of imitative origin.]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.tinnitus (?t?n?t?s; t??na?t?s) n (Pathology) pathol a ringing, hissing, or booming sensation in one or both ears, caused by infection of the middle or inner ear, a side effect of certain drugs, etc[C19: from Latin, from tinn?re to ring]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014tin?ni?tus (t??na? t?s, ?t?n ?-) n. a sensation of sound, as ringing, in the ears. [1685?95;