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

The site has produced the oldest known member of the genus Homo and the earliest known Oldowan stone tools on Earth.

From Science Daily • May 16, 2026

The Huaxi Green Pitviper is now the 58th known species in the Trimeresurus genus and only the second from its subgenus recorded in Sichuan Province.

From Science Daily • Apr. 22, 2026

Researchers also detected DNA from a tree genus thought to have disappeared from the region around 400,000 years ago.

From Science Daily • Apr. 17, 2026

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

From Salon • Apr. 12, 2026

Or it is a small plant of the genus Veronia.

From "The Poisonwood Bible" by Barbara Kingsolver