involution

American  

[in-vuh-loo-shuhn] / ˌɪn vəˈlu ʃən /

noun

1. an act or instance of involving or entangling; involvement.

2. the state of being involved.

3. something complicated.

4. Mathematics. a function that is its own inverse.

5. Botany, Zoology.

   1. a rolling up or folding in upon itself.

   2. a part so formed.

6. Biology. retrograde development; degeneration.

7. Physiology. regressive changes in the body, as those occurring with old age.

8. Anthropology, Sociology. growth without evolution, as in a growing agrarian society with increased field labor whose production mechanisms become more complex without increasing yield; diminishing returns.

9. Grammar. a complex construction in which the subject is separated from its predicate by intervening clauses or phrases.

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involution British  

/ ˌɪnvəˈluːʃən /

noun

1. the act of involving or complicating or the state of being involved or complicated

2. something involved or complicated

3. zoology degeneration or structural deformation

4. biology an involute formation or structure

5. physiol reduction in size of an organ or part, as of the uterus following childbirth or as a result of ageing

6. an algebraic operation in which a number, variable, expression etc, is raised to a specified power Compare evolution

7. grammar an involved construction, such as one in which the subject is separated from the predicate by an additional clause

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involution Scientific  

/ ĭn′və-lo̅o̅′shən /

1. A mathematical operation, such as negation, which, when applied to itself, returns the original number.

2. The ingrowth and curling inward of a group of cells, as in the formation of a gastrula from a blastula.

3. A decrease in size of an organ, as of the uterus following childbirth.

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Other Word Forms

• involutional adjective
• superinvolution noun

Etymology

Origin of involution

First recorded in 1605–15; from Latin involūtiōn- (stem of involūtiō “a rolling up; a screw, spiral”); involute, -ion

Example Sentences

This process is called thymic involution, and it reduces the body's ability to produce new T cells.

From Science Daily • Dec. 29, 2025

The efforts so far focus on several industries where involution is particularly pronounced such as steel, coal, batteries, electric vehicles and food delivery.

From The Wall Street Journal • Oct. 19, 2025

“I thought by opening a stall I could escape the involution of looking for work,” one vendor wrote on Xiaohongshu.

From Los Angeles Times • Jun. 27, 2023

"If this can't be halted, the trends in place could lead to a progressive and unsustainable involution of the human capital of most of southern Italy."

From Reuters • Jan. 25, 2023

It belongs to the general type in so far as it is discussed above, but the roots of the determinant are in involution.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

Related Words

• braid
• tendril