isonicotinic acid

noun iso·nic·o·tin·ic acid \ˌī-sō-ˌnik-ə-ˌtin-ik-, -ˌtēn-\

Medical Definition of ISONICOTINIC ACID

: a crystalline acid C₆H₆NO₂ used chiefly in making isoniazid

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

Put-downs with flair

How to use a word that (literally) drives some people nuts.

Test your vocab with our fun, fast game

Ailurophobia, and 9 other unusual fears

Join Us

Merriam-Webster
on Facebook

Merriam-Webster
on Twitter

Bookstore: Digital and Print

Merriam-Webster references for Mobile, Kindle, print, and more.

See All

Other Merriam-Webster Dictionaries