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 of germ

• 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

Family members often touch these surfaces throughout the day, especially when preparing food, so regular cleaning helps reduce the spread of germs. —Jessica Safavimehr, Southern Living, 27 Feb. 2026

While most healthy people will recover from an illness caused by harmful germs in raw milk—or in foods made with raw milk—within a short time, some can develop symptoms that are chronic, severe, or even life-threatening. —Michele Laufik, Martha Stewart, 26 Feb. 2026

Worth checking out This Saniderm Tattoo Aftercare Bandage protects your new skin from harmful bacteria and germs as your new tattoo heals. —Bestreviews, Chicago Tribune, 25 Feb. 2026

This combination can also help eliminate germs and disinfect granite surfaces. —Caitlin Sole, Better Homes & Gardens, 25 Feb. 2026

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