life cycle

American  

noun

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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Etymology

Origin of life cycle

First recorded in 1870–75

Example Sentences

An IPO used to mark the beginning of an investible company’s life cycle.

From Barron's • May 21, 2026

The team is focused on what is known as “embodied carbon”—the emissions produced during the entire life cycle of construction, including manufacturing, transporting, installing and disposing of materials.

From The Wall Street Journal • May 8, 2026

Their life cycle is complex as they spawn in the Sargasso Sea in the North Atlantic Ocean before travelling to Europe.

From BBC • May 7, 2026

Not surprisingly, the likelihood of high-positive, low-positive and neutral descriptions declined throughout the life cycle, while the high-negative category increased sharply among the oldest sellers.

From MarketWatch • Apr. 13, 2026

To understand how a black hole might be formed, we first need an understanding of the life cycle of a star.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Related Words

• biological clock