genus

American  

[jee-nuhs] / ˈdʒi nəs /

noun

plural

genera, genuses

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 /

plural

genera

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

• pseudogenus noun

Etymology

Origin of genus

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

Example Sentences

According to Scheffrahn, the insect's appearance was so unusual that researchers initially believed they might be looking at an entirely new genus.

From Science Daily • Apr. 1, 2026

Leafhoppers in this genus appear almost identical externally, making visual identification extremely difficult.

From Science Daily • Mar. 11, 2026

Genetic analysis confirmed that the organism represents not only a newly identified species but also an entirely new genus.

From Science Daily • Mar. 6, 2026

While some members of this genus can cause infections in people or animals, they are also considered promising for biotechnology applications.

From Science Daily • Feb. 21, 2026

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

From "Silent Spring" by Rachel Carson