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

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

Dr. David Schwimmer, a leading authority on the massive North American crocodilian genus Deinosuchus and a geology professor at Columbus State University, has helped bring a prehistoric giant back to life.

From Science Daily • Apr. 15, 2026

Choudhury, whose favorite genus is the classic Tyrannosaurus, says he’d love to see more obscure prehistoric species.

From Salon • Apr. 12, 2026

Few, if any, miss the chance to capitalize the genus in their reply.

From Salon • Apr. 12, 2026

However, this marks the first new genus of Early Jurassic ichthyosaur described from the region in more than 100 years.

From Science Daily • Feb. 24, 2026

To clarify this point, I will often use the term ‘Sapiens’ to denote members of the species Homo sapiens, while reserving the term ‘human’ to refer to all extant members of the genus Homo.

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