life cycle

American  

noun

life cycles plural

1. Biology. the continuous sequence of changes undergone by an organism from one primary form, as a gamete, to the development of the same form again.

2. a series of stages, as childhood and middle age, that characterize the course of existence of an individual, group, or culture.

3. any similar series of stages.

   the life cycle of a manufactured product.

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life cycle British  

noun

1. the series of changes occurring in an animal or plant between one development stage and the identical stage in the next generation

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life cycle Scientific  

1. The series of changes in the growth and development of an organism from its beginning as an independent life form to its mature state in which offspring are produced. In simple organisms, such as bacteria, the life cycle begins when an organism is produced by fission and ends when that organism in turn divides into two new ones. In organisms that reproduce sexually, the life cycle may be thought of as beginning with the fusion of reproductive cells to form a new organism. The cycle ends when that organism produces its own reproductive cells, which then begin the cycle again by undergoing fusion with other reproductive cells. The life cycles of plants, algae, and many protists often involve an alternation between a generation of organisms that reproduces sexually and another that reproduces asexually.

2. See more at alternation of generations

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Other Word Forms

Noun Inflected Forms

• life cycles
  plural

Etymology

Origin of life cycle

First recorded in 1870–75

Example Sentences

See Examples For:

life cycle

Charlotte Carne, programmes manager at the SRT, said researchers were still uncovering basic details about the insect's life cycle.

From BBC ● Jul. 9, 2026

Each was an intricate interpretation of an insect at a specific stage of its life cycle.

From The Wall Street Journal ● Jul. 5, 2026

The team also conducted a life cycle analysis and found that the new approach creates less environmental pollution over its full lifespan than existing DAC technologies.

From Science Daily ● Jun. 11, 2026

“We want to look at the full life cycle … not only thinking from the cradle to the grave, but from the point where the raw materials are extracted at the beginning,” Stanton says.

From Los Angeles Times ● Jun. 5, 2026

Fungi are an essential part of the life cycle on earth.

From "The Omnivore's Dilemma" by Michael Pollan

Related Words

• biological clock