Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

Rn

symbol
See What's Trending Now See More Trending Words

Definition of Rn

radon
1

RN

noun \ ˌär-ˈen \

Definition of RN

: registered nurse

See RN defined for English-language learners

See RN defined for kids

First Known Use of rn

1903

in the meaning defined above

See Words from the same year
NEW! Time Traveler
2

RN

abbreviation

Definition of RN

Royal Navy

See RN defined for English-language learners

Medical Dictionary

Rn

symbol

medical Definition of Rn

radon

RN

noun \ ˈär-ˈen \

medical Definition of RN

: registered nurse

Seen and Heard

What made you want to look up Rn? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

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

WORD OF THE DAY

petard

play

a case containing an explosive

Get Word of the Day daily email!

TRENDING NOW

  1. embolization 'the process by which a blood vessel or organ is obstructed by a material mass'

  2. oleaginous 'marked by an offensively ingratiating manner or quality'

  3. pansexual 'sexual desire or attraction...not limited to a particular gender identity or sexual orientation'

  4. symbiote 'an organism living in symbiosis'

  5. charlatan 'faker or fraud'

SEE ALL

BROWSE DICTIONARY

rms
rmt
Rn
RN
RNA

Test Your Vocabulary

May 2018 Words of the Day Quiz

  • spring-flowers
  • Which is a synonym of raillery?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Citation

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

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

Words at Play

image564383649
12 Words from All Over the Map

Some words say exactly where they're from

alt-5b032d1aef0e9
'Ingenious' and 'Ingenuous': More Than a Typo

One's clever, the other's like a child

alt-5b0310daaafde
A Matter-of-Fact Look at 'Deadpan'

Surely we can be serious.

image1481409085
9 Words from the Magical Realm

When language is magic

Ask the Editors

video-ghost-words
Ghost Word

The story of an imaginary word that managed to sneak past our editors and enter the dictionary.

image1760257654
2017 Word of the Year: Behind the Scenes

How we chose 'feminism'

video-literally
Literally

How to use a word that (literally) drives some people nuts.

video-his-or-her
Is Singular 'They' a Better Choice?

The awkward case of 'his or her'

Word Games

spring-flowers
May 2018 Words of the Day Quiz

We’re already at the end of May?!

Take the quiz
image1676440788
Words Used by Nabokov Quiz

How familiar are you with Nabokov’s unfamiliar vocabulary?

Take the quiz
Spell It
Spell It

Can you spell these 10 commonly misspelled words?

Take the quiz
Citation
Citation

Do you know the person or title these quotes describe?

Play the game