penetrate

verb

pen·​e·​trate ˈpe-nə-ˌtrāt 

penetrated; penetrating

transitive verb

1

a

: to pass into or through

This route … penetrates the leading resort and lake areas …

—American Guide Series: Minnesota

Only a dirt road penetrates the rough, wooded terrain.

b

: to enter by overcoming resistance : pierce

This bullet can penetrate armor.

c

: to gain entrance to

… an apartment that I now penetrated for the first time …

—Osbert Lancaster

2

a

: to see into or through

Their keen eyes can penetrate the water to a depth of … forty feet.

—L. K. Porritt

b

: to discover the inner contents or meaning of

… a scientific secret which will eventually be penetrated by other countries …

—Vera M. Dean

3

: to affect profoundly with feeling

Men may still be penetrated with awe by the Divine righteousness …

—R. W. Dale

4

: to diffuse through or into

… the cold began to penetrate his bones.

—E. K. Gann

intransitive verb

1

a

: to pass, extend, pierce, or diffuse into or through something

… fishes … which enter tidal rivers and penetrate almost to fresh water …

—J. L. B. Smith

b

: to pierce something with the eye or mind

strained his eyes to penetrate beyond the thick cloud of dust

insight that penetrates to the very heart of some … problem

—W. F. Hambly

2

: to affect deeply the senses or feelings

… the suggestion might penetrate deeply enough … to make her a good deal more wary …

—H. A. Overstreet

Synonyms of penetrate

• pierce
• enter
• access

Choose the Right Synonym for penetrate

enter, penetrate, pierce, probe mean to make way into something.

enter is the most general of these and may imply either going in or forcing a way in.

entered the city in triumph

penetrate carries a strong implication of an impelling force or compelling power that achieves entrance.

the enemy penetrated the fortress

pierce means an entering or cutting through with a sharp pointed instrument.

pierced the boil with a lancet

probe implies penetration to investigate or explore something hidden from sight or knowledge.

probed the depths of the sea

Examples of penetrate in a Sentence

These bullets can penetrate armor.

radiation penetrating the Earth's atmosphere

The bullet failed to penetrate.

The heat penetrated through the wall.

The roots of these plants have been known to penetrate to a depth of more than 15 feet.

My car's headlights couldn't penetrate the dense fog.

Recent Examples on the Web

The award, announced Monday, covers Low-Profile Mast systems that use telescoping sensor equipment instead of traditional hull-penetrating periscopes. — Sujita Sinha, Interesting Engineering, 23 Sep. 2026

That story centers on the immense commercial potential unlocked by AI agents penetrating everyday consumer markets. — CNBC, 23 Sep. 2026

One big debate about ribs is whether to remove the thin membrane on the back of the bones, which can have a chewy texture and prevent the sauce from penetrating the meat. — ABC News, 23 Sep. 2026

Foremost among these is Google, whose Chromebook laptops and Google Workspace for Education software have penetrated a super-majority of districts; Apple and Microsoft’s devices and classroom software hold a more modest share of the K-12 market. — Jessica Winter, New Yorker, 17 Sep. 2026

Word History

Etymology

Latin penetratus, past participle of penetrare, from penitus deep within, far; akin to Latin penus provisions

First Known Use

circa 1530, in the meaning defined at transitive sense 1a

Phrases Containing penetrate

• penetrate someone's disguise

Rhymes for penetrate

• abdicate
• abrogate
• acetate
• activate
• actuate
• aggravate
• agitate
• alginate
• alienate
• allocate
• amputate
• angulate

Kids Definition

penetrate

verb

pen·​e·​trate ˈpen-ə-ˌtrāt 

penetrated; penetrating

1

a

: to pass into or through

b

: to enter by piercing

2

: to come to understand

3

: to move deeply

Medical Definition

penetrate

verb

pen·​e·​trate ˈpen-ə-ˌtrāt 

penetrated; penetrating

transitive verb

1

: to pass into or through

enzymes that help the sperm penetrate the zona pellucida

—Anna Maria Gillis

2

: to insert the penis into the vagina of in copulation

intransitive verb

: to pass, extend, pierce, or diffuse into or through something

penetrating percutaneous nephroscopy or ureteroscopy

—R. A. Riehle et al.