Where does “gammaproteobacterium” come from?

gammaproteobacterium (English) comes from Translingual Gammaproteobacteria, from Translingual Proteobacteria, from Translingual bacteria, from Ancient Greek βακτήριον, from Ancient Greek βακτηρία, from Proto-Indo-European baḱ- — club, pointed stick, peg; pointed stick, peg.

gammaproteobacterium (English): Any proteobacterium of the class Gammaproteobacteria

Definitions

Any proteobacterium of the class Gammaproteobacteria

Ancestry of “gammaproteobacterium”, step by step

Step	Language	Word	Meaning
1	Translingual	Gammaproteobacteria	class
2	Translingual	Proteobacteria	phylum
3	Translingual	bacteria	A taxonomic domain comprising the single kingdom also called Bacteria, containing about 25 phyla
4	Ancient Greek	βακτήριον	Synonym of βακτηρία
5	Ancient Greek	βακτηρία	rod, staff, cane; baton
6	Proto-Indo-European	baḱ-	club, pointed stick, peg; pointed stick, peg

Every word from Proto-Indo-European baḱ- →Every word from Ancient Greek βακτηρία →Every word from Ancient Greek βακτήριον →