“pentathionic”

We have one entry that includes the term pentathionic.

pentathionic acid

noun

: the thionic acid H2S5O6 containing five atoms of sulfur in the molecule

See the full definition

Word of the Day

Listen to the pronunciation of circumscribe

See Definitions and Examples »

Test Your Vocabulary

Challenging Standardized Test Words, Vol. 2

  • a pencil broken in half on top of a test answer sheet
  • The business’s new computer system proved not to be a panacea.
Spell It

Hear a word and type it out. How many can you get right?

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?
The Missing Letter A daily crossword with a twist
image of a green cube out of place in a lineup of red spheres
Odd Word Out: Synonyms Vol. 2 Quiz Figure out which word isn't like the others.
See All