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

There is no treatment; doctors can offer only supportive care, such as hydration, artificial respiration or dialysis.

From Salon • May 9, 2026

"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

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

This breakdown is driven by biological activity, including predation, clumping of particles, and microbial respiration.

From Science Daily • Feb. 8, 2026

I answer every question correctly and Maestra Eva looks impressed at how the words chlorophyll and respiration and nitrogen-fixing cycle roll off my tongue.

From "The Queen of Water" by Laura Resau