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

• fountainhead
• origin
• root
• seed
• seedbed

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

Letting a pet sleep in the bed isn't without its risks however, as the Sleep Foundation highlights the germ exposure, nighttime disruptions, and potential for territorial behavior. —Alyce Collins, MSNBC Newsweek, 15 May 2025

The three main stages of the disease are primary (exposure), latent (inactive) and active TB, each reflecting whether TB germs are still contained in the lungs or are actively wreaking havoc. —Daryl Austin, USA Today, 11 May 2025

Wash your hands before touching any area of your face to avoid spreading germs through your eyes and mouth. —Anna Giorgi, Verywell Health, 5 May 2025

The bacterial infection, also known as TB, spreads by breathing in the germs of an infected person. —Michelle Marchante, Miami Herald, 1 May 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