thi·​ol | \ ˈthī-ˌȯl How to pronounce thiol (audio) , -ˌōl \

Definition of thiol

1 : any of various compounds having the general formula RSH which are analogous to alcohols but in which sulfur replaces the oxygen of the hydroxyl group and which have disagreeable odors
2 : the functional group −SH characteristic of thiols

Keep scrolling for more

Other Words from thiol

thiolic \ thī-​ˈȯ-​lik How to pronounce thiolic (audio) \ adjective

Examples of thiol in a Sentence

Recent Examples on the Web The skunk bath recipe works by oxidizing the thiols into compounds called disulfides, which are not so smelly. Janine M. Kahn, Good Housekeeping, "What You Should Do When Your Dog Rolls In These 3 Disgusting Things—According To Veterinarians," 10 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thiol.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of thiol

circa 1890, in the meaning defined at sense 1

History and Etymology for thiol

International Scientific Vocabulary thi- + -ol entry 1

Keep scrolling for more

Learn More about thiol

Time Traveler for thiol

Time Traveler

The first known use of thiol was circa 1890

See more words from the same year

Statistics for thiol

Cite this Entry

“Thiol.” Dictionary, Merriam-Webster, Accessed 26 Sep. 2020.

Keep scrolling for more

More Definitions for thiol


thi·​ol | \ ˈthī-ˌȯl How to pronounce thiol (audio) , -ˌōl How to pronounce thiol (audio) \

Medical Definition of thiol

1 : any of a class of compounds that are analogous to alcohols and phenols but contain sulfur in place of oxygen with the general formula RSH and in the case of those of low molecular weight have very disagreeable odors

called also mercaptan

2 : the functional group −SH characteristic of thiols

Other Words from thiol

thiolic \ thī-​ˈō-​lik How to pronounce thiolic (audio) \ adjective

More from Merriam-Webster on thiol Encyclopedia article about thiol

Comments on thiol

What made you want to look up thiol? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Challenging Vocabulary Quiz Returns!

  • stylized drawing of woman pole vaulting across gap to get trophy
  • Which is a synonym of fuliginous?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!