# genus

Pronunciation: say "JEE-nuhs" US /ˈd͡ʒiːnəs/, UK /ˈdʒiːnəs/

## Noun

1. In biology, a rank in classifying living things, below family and above species, or a group of related species at that rank; its name begins a two-part scientific name.
   - Simple: In biology, a group of closely related kinds of living things. Its name is the first word of a scientific name.
   - _Lions, tigers and leopards all belong to the genus Panthera._
   - _Botanists moved the plant to a new genus after DNA tests revealed its closest relatives._
2. A group or class of things that share common attributes.
   - Simple: A group of things that are alike in some ways.
3. A natural number giving any of several related measures of how complex a particular manifold or graph is.
   - Simple: A whole number used in math to measure how complex a surface or network is.
   - _A sphere has genus zero, while a torus has genus one._
   - _The genus of a graph is the smallest genus of a surface on which it can be drawn without any edges crossing._
4. In a definition, the broader category to which the defined concept belongs.
   - Simple: In a definition, the bigger group that the thing being defined belongs to.
   - _A classical definition names the genus first and then the features that set the term apart within it._
   - _If a sofa is defined as a long upholstered seat, then seat is the genus._

## Other meanings

- (noun) One of the types of tuning or intonation used within a tetrachord in ancient Greek music.

## Origin

Latin genus, which covered "birth, origin, a race, sort, kind," was taken directly into English. It is built on the root gen- found in Latin gignō ("to beget, produce"). Gender and genre are doublets, and kin is a more distant relative.

Source: DictionaryAI, https://dictionaryai.com/define/genus (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).