germ

noun

ˈjərm 

plural germs

1

a

: a small mass of living substance capable of developing into an organism or one of its parts

b

: the embryo with the scutellum of a cereal grain that is usually separated from the starchy endosperm during milling

2

: something that initiates development or serves as an origin : rudiments, beginning

3

: a microorganism causing disease : a pathogenic agent (such as a bacterium or virus)

broadly : microorganism

Synonyms

• origin
• root
• seed
• beginning

Examples of germ in a Sentence

the germ that causes tuberculosis

the germ of an idea

the germ layers of an embryo

Recent Examples on the Web

Always assume items have unseen germs or pests and clean them accordingly before bringing them into your home. —Brandee Gruener, Southern Living, 29 June 2025

Scrub your way across the surface to dislodge any final particles and help remove germs and bacteria, then rinse the grill grates well with fresh water. —Karla Walsh, Better Homes & Gardens, 28 June 2025

While most types of E. coli are harmless and help us digest food, produce vitamins, and protect us from harmful germs, according to the CDC, some cases lead to diarrhea, urinary tract infections, pneumonia, sepsis and other serious illnesses. —Moná Thomas, People.com, 27 June 2025

This is advantageous because each type of bacteria performs different jobs, like breaking down food, strengthening the gut lining, and fighting harmful germs. —Matt Fuchs, Time, 17 June 2025

Word History

Etymology

French germe, from Latin germin-, germen, from gignere to beget — more at kin

First Known Use

circa 1550, in the meaning defined at sense 2

Phrases Containing germ

• germ cell
• germ-free
• germ layer
• germ line
• germ plasm
• germ theory
• germ warfare
• wheat germ

Rhymes for germ

• berm
• ferm
• firm
• herm
• sperm
• squirm
• term
• therm
• worm
• wurm
• affirm
• bookworm

Kids Definition

germ

noun

ˈjərm 

1

a

: a small mass of living substance capable of developing into a whole individual or one of its parts

b

: the embryo in the seed of a cereal (as corn or wheat) together with its cotyledon that is usually separated from the starchy part of the seed during milling

2

: something that serves as an origin

the germ of an idea

3

: a microscopic living thing

especially : one that causes disease

Medical Definition

germ

noun

ˈjərm 

1

: a small mass of living substance capable of developing into an organism or one of its parts

2

: a microorganism causing disease : a pathogenic agent (as a bacterium or virus)

broadly : microorganism