“1-25”

The following 2 entries include the term 1-25.

1,25-dihydroxycholecalciferol

noun

: calcitriol

See the full definition

iodine-125

noun

: a light radioactive isotope of iodine that has a mass number of 125 and a half-life of 60 days, gives off soft gamma rays, and is used as a tracer in thyroid studies and as therapy in hyperthyroidism

See the full definition

Word of the Day

Listen to the pronunciation of risible

See Definitions and Examples »

Test Your Vocabulary

Fashionable Words

  • dog-sunglasses-scarf
  • Which of these items is named for a deadly weapon?
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 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
chain-with-string
Fastest Quiz Ever: Missing Link Five seconds to figure out the word that fits bot...
See All