Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018British Dictionary definitions for ad nauseam
Latin: to (the point of) nausea
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for ad nauseam
"to a sickening extent," Latin, literally "to sickness" (see nausea).
Online Etymology Dictionary, © 2010 Douglas Harper
To go on endlessly; literally, to continue “to seasickness”: “The candidate told us the details of how he overcame his childhood problems ad nauseam.”
The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with ad nauseam
To ridiculous excess, to a sickening degree. For example, I wish he'd drop the subject; we have heard about budget cuts ad nauseam. The term, Latin for “to [the point of] nausea,” has been used in English since the early 1600s.
The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.