respiration

American  

[res-puh-rey-shuhn] / ˌrɛs pəˈreɪ ʃən /

noun

1. the act of respiring; inhalation and exhalation of air; breathing.

2. Biology.

   1. the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells, and the oxidation products, carbon dioxide and water, are given off.

   2. an analogous chemical process, as in muscle cells or in anaerobic bacteria, occurring in the absence of oxygen.

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respiration British  

/ ˌrɛspəˈreɪʃən /

noun

1. the process in living organisms of taking in oxygen from the surroundings and giving out carbon dioxide ( external respiration ). In terrestrial animals this is effected by breathing air

2. the chemical breakdown of complex organic substances, such as carbohydrates and fats, that takes place in the cells and tissues of animals and plants, during which energy is released and carbon dioxide produced ( internal respiration )

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respiration Scientific  

/ rĕs′pə-rā′shən /

1. The process by which organisms exchange gases, especially oxygen and carbon dioxide, with the environment. In air-breathing vertebrates, respiration takes place in the lungs. In fish and many invertebrates, respiration takes place through the gills. Respiration in green plants occurs during photosynthesis.

2. See cellular respiration

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respiration Cultural  

1. The conversion of oxygen by living things into the energy by which they continue life. Respiration is part of metabolism.

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Discover More

Carbon dioxide is a waste product of respiration.

Other Word Forms

• prerespiration noun
• respirational adjective

Etymology

Origin of respiration

1400–50; late Middle English respiracioun < Latin respīrātiōn- (stem of respīrātiō ) a breathing out, equivalent to respīrāt ( us ) (past participle of respīrāre to respire ) + -iōn- -ion

Explanation

Respiration is the act of breathing. You wear a ventilator if you need help with your respiration. Everyone who breathes has the power of respiration. There is, however, another type of respiration which occurs in cells. This is the process of taking in certain substances and putting out others that a cell undergoes to produces energy. One single breath, the inhale and the exhale together, is also called a respiration.

Example Sentences

"We propose that the system found in Captorhinus represents the ancestral condition for the kind of rib assisted respiration present in living reptiles, birds, and mammals" said Reisz.

From Science Daily • Apr. 23, 2026

He studied the prevention and cure of disease and how the body functioned, including respiration and blood circulation, and he had a nascent understanding of germs.

From The Wall Street Journal • Apr. 14, 2026

In “Grass Breathing,” Mendieta, hidden beneath squares of sod, uses her own respiration to animate the earth above.

From The Wall Street Journal • Mar. 15, 2026

Understanding how respiration and photosynthesis interact through oxygen exchange offers a clearer picture of plant energy metabolism.

From Science Daily • Mar. 9, 2026

Then by careful measurements of their respiration, it was found that the fermentation rate was markedly above normal, just as Warburg had foreseen.

From "Silent Spring" by Rachel Carson