T, abbreviation for thyronine + 3, number of iodine atoms attached to the thyronine nucleus
1956, in the meaning defined above
“T3.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/T3. Accessed 31 Jan. 2023.
Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!
See Definitions and Examples »
Get Word of the Day daily email!
Commonly Confused Words Quiz
Test your knowledge - and maybe learn something along the way.
Can you make 12 words with 7 letters?
A lexicographer's best friend
More words, more beautiful, more useless
Spelling isn't all black and white.
Look up any year to find out
One goose, two geese. One moose, two... moose. Wh...
It is in fact a real word (but that doesn't mean ...
Both words imply motion, but the difference may b...
The fascinating story behind many people's favori...
"Leggings" or "mom jeans"? "Chillax" or "dumpster...
Take the quiz
Test your visual vocabulary!
Test your knowledge - and maybe learn something a...
Can you outdo past winners of the National Spelli...