Dictionary
Thesaurus
Medical
Scrabble®
Spanish Central
Browse DictionaryBrowse Thesaurus
Get our free apps!iPhone•iPad•Android
Games
Word of the Day
Video
Blog: Words at Play
My Faves
Dictionary

RR

abbreviation

Definition of RR

1
railroad
2
rural route
See RR defined for English-language learners
ADVERTISEMENT
RR Defined for Kids

RR

abbreviation

Definition of RR for Kids

railroad
Medical Dictionary

RR

abbreviation

Medical Definition of RR

recovery room

Browse

4 ENTRIES FOUND:
  1. RR
  2. Victoria Fast Violet RR
  3. R & R
  4. R and R
Next Word in the Dictionary: RRCPrevious Word in the Dictionary: rqnAll Words Near: RR
ADVERTISEMENT
10 Charming Words for Nasty People
Put-downs with flair
Learn More
When "Literally" isn't, well, literal
How to use a word that (literally) drives some people nuts.
Watch Now
Know what this is?
Test your vocab with our fun, fast game
Go Play
Fear of cats?
Ailurophobia, and 9 other unusual fears
Learn More
Join Us
Merriam-Webster
on Facebook
Merriam-Webster
on Twitter
Bookstore: Digital and Print
Merriam-Webster references for Mobile, Kindle, print, and more.
See All
Other Merriam-Webster Dictionaries