genus
Americannoun
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Biology. the usual major subdivision of a family or subfamily in the classification of organisms, usually consisting of more than one species.
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Logic. a class or group of individuals, or of species of individuals.
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a kind; sort; class.
noun
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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 )
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logic a class of objects or individuals that can be divided into two or more groups or species
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a class, group, etc, with common characteristics
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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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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.”
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See Table at taxonomy
Other Word Forms
Derived Forms
Inflected Forms
Nouns
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.
Vocabulary lists containing genus
"The Origin of Species by Natural Selection" by Charles Darwin: Essential Words
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We the People: Gen
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The ACT Science Test: Biology Review 1
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
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
At first, researchers placed the Ajimu fossils in the genus Andrias, which contains the largest amphibians alive today.
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
The spider, which belongs to the genus Propostira, was initially observed by biomedical researcher Greg Anderson - also a spider researcher and photographer.
From BBC ● Jun. 23, 2026
Being a human belonging to the wallflower genus, I’m kinda used to swallowing my words instead of speaking them.
From "From Twinkle, with Love" by Sandhya Menon
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Dr Matthew McCurry, Curator of Palaeontology, Australian Museum, said the discovery of three new genera of monotremes helps to piece together their remarkable evolutionary story.
From Science Daily ● May 27, 2024
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
The subfamilies are major subdivisions of the family, while the tribes and subtribe can contain one or more of genera, which is the classification level just above the species.
From Science Daily ● Apr. 3, 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
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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
There are more than 100 species of Nepenthes, which is one of the many genuses of carnivorous plants found around the world.
From New York Times ● May 18, 2022
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
Then I goes to the old 'uns, and says to them, what genuses for music these young 'uns be! it is your duty to improve a talent that providence has bestowed on your children.
From Life in the Clearings versus the Bush by Moodie, Susanna
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.