genus

American  

[jee-nuhs] / ˈdʒi nəs /

noun

• genera,
  plural
• genuses
  plural

1. Biology. the usual major subdivision of a family or subfamily in the classification of organisms, usually consisting of more than one species.

2. Logic. a class or group of individuals, or of species of individuals.

3. a kind; sort; class.

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genus British  

/ ˈdʒiːnəs /

noun

1. biology any of the taxonomic groups into which a family is divided and which contains one or more species. For example, Vulpes (foxes) is a genus of the dog family ( Canidae )

2. logic a class of objects or individuals that can be divided into two or more groups or species

3. a class, group, etc, with common characteristics

4. maths a number characterizing a closed surface in topology equal to the number of handles added to a sphere to form the surface. A sphere has genus 0, a torus, genus 1, etc

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genus Scientific  

/ jē′nəs /

• genera
  plural

1. A group of organisms ranking above a species and below a family. The names of genera, like those of species, are written in italics. For example, Periplaneta is the genus of the American cockroach, and comes from the Greek for “wandering about.”

2. See Table at taxonomy

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genus Cultural  

1. In biology, the classification lower than a family and higher than a species. Wolves belong to the same genus as dogs. Foxes belong to a different genus from that of dogs and wolves, but to the same family. (See Linnean classification.)

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Other Word Forms

Derived Forms

• pseudogenus
  noun

Inflected Forms

Nouns

• genera
  plural
• genuses
  plural

Etymology

Origin of genus

1545–55; < Latin: race, stock, kind, gender; cognate with Greek génos. See gens, gender ¹, kin

Explanation

A genus is a class or group of something. In biology, it's a taxonomic group covering more than one species. This is a term used by biologists to classify more than one species under a larger umbrella. In biology, the word family describes the broadest group category, then genus, and then species. For example, primates are a family, and humans are a species within that family, but we're not in the same genus as macaques: macaques have their own genus. Dogs and wolves are so closely related they’re in the same genus. The plural of genus is genera.

Example Sentences

See Examples For:

genus genera genuses

Leafcutter ants cultivate fungus for food, while ants of the Lasius genus tend aphids for their sweet secretions “like domestic cattle.”

From The Wall Street Journal ● Aug. 3, 2026

Based on those differences, the team concluded that the fossils belonged to both a previously unknown species and a new genus.

From Science Daily ● Jul. 24, 2026

However, limited anatomical knowledge has caused many specimens to be assigned to the living genus Andrias.

From Science Daily ● Jul. 24, 2026

Jones said the best way to spot healthy peatland was the plants growing on it, "there'll be grasses, sedges, heathers, critically there will often be bog mosses of the genus sphagnum".

From BBC ● Jul. 3, 2026

Mosquitoes of the genus Anopheles may inject into the human bloodstream the single-celled organism of malaria.

From "Silent Spring" by Rachel Carson

For example, the same bacterial genera showed glyphosate resistance across all three environments.

From Science Daily ● Jun. 23, 2026

However, several bacterial genera were more common in individuals that skipped the hot springs.

From Science Daily ● Mar. 3, 2026

In the end, the team used data from about 60 percent of all modern genera of plants.

From New York Times ● May 11, 2024

Using this method, the team sequenced part of the nuclear genomes from about 8000 genera of angiosperms—about 60% of all flowering plants on Earth—and compared 353 of their genes.

From Science Magazine ● Apr. 23, 2024

According to current estimates, within that short interval, North America lost thirty-four out of its forty-seven genera of large mammals.

From "Sapiens: A Brief History of Humankind" by Yuval Noah Harari

Almost 300 biologists have banded together and redrawn the tree of life for flowering plants, enabling a 15-fold increase in the number of genuses represented and highlighting new milestones in diversification.

From Science Magazine ● Apr. 24, 2024

This uncanny deadliness has a mystery at its core: These mushrooms are from three separate genuses, or groups of fungal species, that are not closely related.

From New York Times ● May 9, 2022

Anemone and Aster are large genuses in their own right, filled with poppy- and daisy-like blooms.

From Slate ● May 17, 2016

Paleontologists have documented five new genuses of dinosaurs and six previously unknown species since research began in the 1980s in partnership with French scientists.

From New York Times ● Jul. 13, 2010

The children like to hear themselves called genuses, and they go into it like smoke.

From Life in the Clearings versus the Bush by Susanna Moodie