“protein-bound”

We have one entry that includes the term protein-bound.

protein-bound iodine

noun

: the amount of iodine expressed in micrograms per 100 milliliters of blood serum that is precipitated with serum proteins and that serves as a measure of the activity of the thyroid gland

See the full definition

Word of the Day

Listen to the pronunciation of guttural

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.
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 Word Game 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
little chihuahua dressing like a turkey for thanksgiving
Is That Gratitude or Attitude? A Thanksgiving Quiz Decide which words express gratitude and which gi...