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.

---

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

---

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

---

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.)

---

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

The public naming campaign began after Ze Frank featured the rare deep-sea chiton from the genus Ferreiraella in an episode of his "True Facts" YouTube series.

From Science Daily • Feb. 7, 2026

The newly identified species, named Araneothrombium brasiliensis, belongs to a genus first described in Costa Rica in 2017.

From Science Daily • Jan. 28, 2026

The study, titled "First Afar Paranthropus fossil expands the distribution of a versatile genus," was published in Nature in January 2026.

From Science Daily • Jan. 23, 2026

Paranthropus has long been labeled the "nutcracker" genus, a nickname inspired by its massive jaws, thick tooth enamel, and oversized molars.

From Science Daily • Jan. 23, 2026

Marie-Laure is not a collector in the way that Dr. Geffard was, an amasser, always looking to scurry down the scales of order, family, genus, species, and subspecies.

From "All the Light We Cannot See" by Anthony Doerr