ID50

symbol

—used for the dose of an infectious organism required to produce infection in 50 percent of the experimental subjects

Dictionary Entries Near ID50

id

ID50

IDA

Cite this Entry

“ID50.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/ID50. Accessed 2 Jan. 2025.

Copy Citation

Share

Love words? Need even more definitions?

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

Popular in Grammar & Usage

See All

31 Useful Rhetorical Devices

Using Bullet Points ( • )

'Gray' vs. 'Grey': What is the difference?

What's the difference between 'fascism' and 'socialism'?

More Commonly Misspelled Words
See All

Popular in Wordplay

See All

Terroir, Oenophile, & Magnum: Ten Words About Wine

8 Words with Fascinating Histories

8 Words for Lesser-Known Musical Instruments

Birds Say the Darndest Things

10 Words from Taylor Swift Songs (Merriam's Version)
See All

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
tiny woman sitting on a pile of books reading
Little Words, Big Vocabulary Quiz Time to sweat the small stuff.