spleen

American  

[spleen] / splin /

noun

• spleens
  plural

1. a highly vascular, glandular, ductless organ, situated in humans at the cardiac end of the stomach, serving chiefly in the formation of mature lymphocytes, in the destruction of worn-out red blood cells, and as a reservoir for blood.

2. Obsolete. this organ conceived of as the seat of spirit and courage or of such emotions as mirth, ill humor, melancholy, etc.

3. ill humor, peevish temper, or spite.

   Synonyms:

   anger, ire, wrath, acrimoniousness, rancor, petulance

4. Archaic. melancholy.

5. Obsolete. caprice.

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spleen British  

/ spliːn /

noun

1. a spongy highly vascular organ situated near the stomach in man. It forms lymphocytes, produces antibodies, aids in destroying worn-out red blood cells, and filters bacteria and foreign particles from the blood

2. the corresponding organ in other animals

3. spitefulness or ill humour; peevishness

   to vent one's spleen

4. archaic the organ in the human body considered to be the seat of the emotions

5. archaic another word for melancholy

6. obsolete whim; mood

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spleen Scientific  

/ splēn /

1. An organ in vertebrate animals that in humans is located on the left side of the abdomen near the stomach. The spleen is mainly composed of lymph nodes and blood vessels. It filters the blood, stores red blood cells (erythrocytes) and destroys old ones, and produces white blood cells (lymphocytes).

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spleen Cultural  

1. An organ in the lymphatic system, in the upper left part of the abdomen, that filters out harmful substances from the blood. The spleen also produces white blood cells, removes worn-out red blood cells from circulation, and maintains a reserve blood supply for the body.

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spleen Idioms  

1. see vent one's spleen.

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Other Word Forms

Derived Forms

• spleenish
  adjective
• unspleenish
  adjective
• unspleenishly
  adverb

Inflected Forms

Nouns

• spleens
  plural

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Etymology

Origin of spleen

1250–1300; Middle English < Latin splēn < Greek splḗn; akin to Sanskrit plīhan, Latin liēn spleen

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Explanation

The spleen is an organ that's about the size of a fist, located on the left side, just below the ribcage. Don't let its small size fool you. This little organ is very important in helping the body fight infection. The spleen is responsible for removing old red blood cells and producing and storing a reserve of blood in case the body needs it. It's a little organ, measuring little more than four inches in length. The term "vent your spleen" is one you might see used. It means to vent your anger, as spleen is another word for bad temper or spite.

Example Sentences

See Examples For:

spleen spleens

The treatment also improved disease-related changes in the thymus and spleen, two organs that play important roles in the immune system.

From Science Daily ● Oct. 22, 2026

The treatment also eliminated cancer from both the bone marrow and spleen.

From Science Daily ● Oct. 7, 2026

Lancaster County coroner Stephen Diamantoni, a Republican, has said one of the two infants died of a ruptured spleen rather than measles itself.

From BBC ● Sep. 24, 2026

A forensic pathologist in his office determined the infant died from a ruptured spleen and the pathologist said, in his opinion, that the cause of death was unrelated to measles.

From The Wall Street Journal ● Sep. 4, 2026

There followed, of course, the usual gallbladder, spleen, and kidney operations.

From "The Milagro Beanfield War" by John Nichols

They were looking at “scurfy” mice; males are unexpectedly born with flaky skin and enlarged spleens and only live for a few weeks, because their organs are attacked by their own immune cells.

From The Wall Street Journal ● Oct. 6, 2025

Erewhon says the mix of uncooked beef livers, hearts, pancreases, kidneys and spleens swirling through the coconut cream in the beverage should not be considered “raw.”

From Los Angeles Times ● Jul. 18, 2024

The study documents germinal center–like structures in the spleens of rainbow trout, the first time anyone has detected them in bony fish.

From Science Magazine ● Oct. 31, 2023

Yet this bedrock right to vent our spleens against officials is now being challenged.

From Salon ● Mar. 26, 2021

These spleens were the size of a tangerine and were leathery.

From "The Hot Zone" by Richard Preston

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Related Words

• ill humor
• ill temper
• peevishness

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