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

Chicken and turkey carried the highest-risk strains of bacteria, but pork and beef also carried the illness-causing germs. —Cara Lynn Shultz, PEOPLE, 24 Oct. 2025

In Toilet Base Regularly cleaning your toilet with water and vinegar will keep the smells away, but will also clean any of the germs that fester in and around your toilet and make the area stink, according to Knoll. —Daley Quinn, Southern Living, 23 Oct. 2025

Dirt and germs breed bad odors. —Nafeesah Allen, Better Homes & Gardens, 21 Oct. 2025

The immune system typically prevents these germs from causing infection in the lungs, but some can still evade the body's defenses, even if a person is in good health, according to the Mayo Clinic. —Rebecca Cohen, NBC news, 16 Oct. 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