SINCE 1828

An Encyclopædia Britannica Company

Medical Dictionary

iliocostalis lumborum

play

noun iliocostalis lum·bor·um \ -ˌləm-ˈbȯr-əm \

medical Definition of iliocostalis lumborum

:a muscle that extends from the ilium to the lower ribs and acts to draw the trunk to the same side or to depress the ribs

Seen and Heard

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

show

WORD OF THE DAY

shofar

play

a ram's-horn trumpet used in Judaism

Words at Play

alt-59c2960017c94

The Ambiguity of Pushing 'Up' and 'Back'

When you push a meeting, where does it go?

Silent Letters

When each letter can be seen but not heard

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.

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'

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

young-plant-shoots

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

You're going to have to memorize the dictionary again.

Take the quiz

stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy

Challenging Vocabulary Quiz Returns!

No tricks, just difficult words.

Take the quiz

How Strong Is Your Vocabulary?

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz

Bee Cubed

Listen to the words and spell through all three levels.

Play the game