Quiz: Remember the definition of mal de mer?


[mer-kap-tan] /mərˈkæp tæn/
noun, Chemistry
any of a class of sulfur-containing compounds having the type formula RSH, in which R represents a radical, and having an extremely offensive, garlicky odor.
1825-35; < Latin, short for phrase corpus mercurium captāns body capturing quicksilver Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for mercaptan
  • mercaptan is an irritant that can cause respiratory problems, headaches, nausea and vomiting.
  • The intense heat also buckled the rail beneath the methyl mercaptan tank car.
  • Acute and subchronic toxicity studies of rats exposed to vapors of methyl mercaptan and other reduced sulfur compounds.
British Dictionary definitions for mercaptan


another name (not in technical usage) for thiol
Word Origin
C19: from German, from Medieval Latin mercurium captans, literally: seizing quicksilver
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
Cite This Source
mercaptan in Medicine

mercaptan mer·cap·tan (mər-kāp'tān')
Any of a class of organic compounds in which the oxygen of an alcohol has been replaced by sulfur and which have distinctive, often disagreeable, odors. Also called thiol.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
mercaptan in Science
See thiol.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Article for mercaptan

any of a class of organic chemical compounds similar to the alcohols and phenols but containing a sulfur atom in place of the oxygen atom. Thiols are among the odorous principles in the scent of skunks and of freshly chopped onions; their presence in petroleum and natural gas is objectionable because they have disagreeable odours, interfere with catalysts used in refining processes, and produce sulfur dioxide upon combustion.

Learn more about mercaptan with a free trial on
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for mercaptan

Many English speakers likely know this word

Word Value for mercaptan

Scrabble Words With Friends

Nearby words for mercaptan