lung

American  

[luhng] / lʌŋ /

noun

1. either of the two saclike respiratory organs in the thorax of humans and the higher vertebrates.

2. an analogous organ in certain invertebrates, as arachnids or terrestrial gastropods.

---

idioms

1. at the top of one's lungs, as loudly as possible; with full voice.

   The baby cried at the top of his lungs.

lung British  

/ lʌŋ /

noun

1. either one of a pair of spongy saclike respiratory organs within the thorax of higher vertebrates, which oxygenate the blood and remove its carbon dioxide

2. any similar or analogous organ in other vertebrates or in invertebrates

3. in one's loudest voice; yelling

---

lung Scientific  

/ lŭng /

1. Either of two spongy organs in the chest of air-breathing vertebrate animals that serve as the organs of gas exchange. Blood flowing through the lungs picks up oxygen from inhaled air and releases carbon dioxide, which is exhaled. Air enters and leaves the lungs through the bronchial tubes.

2. A similar organ found in some invertebrates.

---

lung More Idioms  

1. see at the top of one's lungs.

---

Other Word Forms

• half-lunged adjective
• lunged adjective

Etymology

Origin of lung

before 1000; Middle English lungen, Old English; cognate with German Lunge; akin to light ², lights

Explanation

A lung is an internal organ that makes it possible for you to breathe. Your lungs remove carbon dioxide from your body while sending oxygen into your blood stream. All vertebrates — animals with a spinal column — have lungs. Humans have two of them, and they're what makes your chest rise and fall as you breathe in and out. They're also the organs that keep you breathing, and therefore alive. Lung, by way of the Old English lungen, comes from an Indo-European root that literally means "the light organ."

Example Sentences

"Particle pollution can get deep into the lungs and cause serious health problems such as asthma attacks, heart and lung disease symptoms, and increased risk of lung infections," the National Weather Service warned.

From BBC • Apr. 11, 2026

When lung growth is hindered in adolescence, “that can lead to increased risk for respiratory, cardiovascular, and metabolic diseases later in life,” said Fangqi Guo, the study’s lead author.

From Los Angeles Times • Apr. 9, 2026

“We’re seeing the impacts of dust events and proximity to the sea as being detrimental to children’s lung development.”

From Los Angeles Times • Apr. 9, 2026

Gilead said TUB-040, Tubulis’ lead asset, is an ADC in Phase 1b/2 development for platinum-resistant ovarian cancer and non-small cell lung cancer.

From The Wall Street Journal • Apr. 7, 2026

He’d been hospitalized with lung issues earlier in the year.

From "Becoming" by Michelle Obama