Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

castor-oil plant

noun

Definition of castor-oil plant

:a tropical Old World herb (Ricinus communis) widely grown as an ornamental or for its oil-rich castor beans

See castor-oil plant defined for kids

Explore Merriam-Webster

stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
Challenging Vocabulary Quiz Returns!
alt-59bab5dbb4997
Trending: 'Bodega' Startup Draws Criticism, Mockery
image2143067130
9 Slang Words With Academic Origins
alt-59c17b8172892
'So Long': A Common But Mysterious Goodbye

First Known Use of castor-oil plant

1836

Medical Dictionary

castor-oil plant

noun

medical Definition of castor-oil plant

:a tropical Old World herb of the genus Ricinus (R. communis) widely grown as an ornamental or for its oil-rich castor beans that are a source of castor oil

Learn More about castor-oil plant

  1. Britannica.com: Encyclopedia article about castor-oil plant

Seen and Heard

What made you want to look up castor-oil plant? 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

glabrous

play

smooth or hairless

Get Word of the Day daily email!

TRENDING NOW

  1. bodega "Don’t mess with the beloved bodega."

  2. carceral Of, relating to, or suggesting a jail or prison

  3. allegory No spoilers!

  4. hurricane 'A tropical cyclone'

  5. rescind To take away; cancel; repeal

SEE ALL

BROWSE DICTIONARY

castor-oil plant

Test Your Vocabulary

Challenging Vocabulary Quiz Returns!

  • stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
  • Which is a synonym of fuliginous?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Syn City

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

alt-59c17b8172892
'So Long': A Common But Mysterious Goodbye

Its origins are surprisingly murky.

alt-59c13729150dc
"Immune to" or "Immune from"?

Nobody is immune to this question.

alt-59bff395cf879
What's Going On With 'Nonplussed'?

Its recent usage is hard to shrug off.

alt-59bad350d88f1
Welcome to the New Words

From 'hive mind' to 'sriracha'

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
Challenging Vocabulary Quiz Returns!

No tricks, just difficult words.

Take the quiz
name-that-color-logo
Name that Color!

NEW! Additional colors! More obscure than before!

Take the quiz
True or False
True or False?

Test your knowledge - and maybe learn something along the way.

Take the quiz
Syn City
Syn City

Build a city of skyscrapers—one synonym at a time.

Play the game