“isonicotinic”

The following 2 entries include the term isonicotinic.

isonicotinic acid

noun

: a crystalline acid C6H6NO2 used chiefly in making isoniazid

See the full definition

isonicotinic acid hydrazide

noun

: isoniazid

See the full definition

Word of the Day

Listen to the pronunciation of apathy

See Definitions and Examples »

Test Your Vocabulary

Commonly Misspelled Words Vol. 2 Quiz

  • sequel spelled three ways with the incorrect ways crossed out and the correct spelling circled
  • Rachel seemed to be _____ in every endeavor she started.
Name That Thing

You know what it looks like… but what is it called?

TAKE THE QUIZ
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.

Pick the best words!

PLAY
Love words? Need even more definitions?

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

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
image of the words cracker fly and sale arranged in a triangle with the word fire in the middle
Triple Play Quiz Find the word that pairs with each of the three g...
See All