“Provitamin A.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/provitamin%20A. Accessed 10 Dec. 2022.
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!
Words Named After People
Test your knowledge - and maybe learn something along the way.
A daily challenge for crossword fanatics.
When each letter can be seen but not heard
Some may be more useful than others.
One L or two?
Look up any year to find out
How to use a word that (literally) drives some pe...
Or both? Or neither?
Editor Emily Brewster clarifies the difference.
An old-fashioned rule we can no longer put up with.
Test your visual vocabulary
Take the quiz
No Number 2 pencil required.
Test your knowledge - and maybe learn something a...
Can you outdo past winners of the National Spelli...