1
as in dense
impossible to get through or into
the ancient temple was surrounded by vast stretches of impenetrable jungle
Synonyms & Similar Words
Relevance
Antonyms & Near Antonyms
2
as in mysterious
being beyond one's powers to know, understand, or explain
the mysteries of that religion are completely impenetrable to outsiders
Synonyms & Similar Words
Antonyms & Near Antonyms
3
as in incomprehensible
impossible to understand
the textbook's language is completely impenetrable, at least to me
Synonyms & Similar Words
Antonyms & Near Antonyms
4
as in tight
not allowing penetration (as by gas, liquid, or light)
the container of toxic waste has an impenetrable seal to prevent leaks
Synonyms & Similar Words
Antonyms & Near Antonyms
Example Sentences
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Recent Examples of impenetrable
Another brick has been laid in One Battle After Another’s impenetrable fortress this awards season.
—
Jason P. Frank, Vulture, 12 Jan. 2026
Miami has rekindled memories of its 2001 national championship team behind a defense that went from porous to nearly impenetrable in its first season under coordinator Corey Hetherman.
—Fiifi Frimpong, New York Daily News, 9 Jan. 2026
Miami has rekindled memories of its 2001 national championship team behind a defense that went from porous to nearly impenetrable in its first season under coordinator Corey Hetherman.
—Dallas Morning News, 8 Jan. 2026
Yes, some of the attacking intent was stripped from recent games, but that was necessary in bolstering their impenetrable deep block at the home of the defending champions.
—Beren Cross, New York Times, 2 Jan. 2026
See All Example Sentences for impenetrable
Jason P. Frank, Vulture, 12 Jan. 2026
Miami has rekindled memories of its 2001 national championship team behind a defense that went from porous to nearly impenetrable in its first season under coordinator Corey Hetherman.
—Fiifi Frimpong, New York Daily News, 9 Jan. 2026
Miami has rekindled memories of its 2001 national championship team behind a defense that went from porous to nearly impenetrable in its first season under coordinator Corey Hetherman.
—Dallas Morning News, 8 Jan. 2026
Yes, some of the attacking intent was stripped from recent games, but that was necessary in bolstering their impenetrable deep block at the home of the defending champions.
—Beren Cross, New York Times, 2 Jan. 2026
See All Example Sentences for impenetrable
Recent Examples of Synonyms for impenetrable
Adjective
-
In cases of near-zero visibility due to dense fog, initiate your hazard lights and locate a secure spot, such as a nearby business parking area, to pull over and come to a halt.—
Bay Area Weather Report,
Mercury News,
21 Jan. 2026
-
In situations of near-zero visibility due to dense fog, activate your hazard lights and seek a secure location, such as a nearby business’s parking lot, to pull over and come to a stop.—
Southern California Weather Report,
Oc Register,
21 Jan. 2026
Adjective
-
People were interacting at workstations with computers, flipping through books on shelves, reading mysterious notes on desks and watching strange videos.—
Jan Wagner,
San Diego Union-Tribune,
21 Jan. 2026
-
If anything, ChatGPT-3 has something of the oracular about it; for as mysterious as the writing process of any author may be in all sorts of intangible and ineffable ways, any person who works in words also understands what’s prosaic and gritty (and thus all the more beautiful) about writing.—
Literary Hub,
Literary Hub,
21 Jan. 2026
Adjective
-
That sentence would’ve sounded incomprehensible to anyone who’d just returned from a decade on a desert island, about as farfetched as Indiana being 15-0 right now.—
Jason Kirk,
New York Times,
16 Jan. 2026
-
The scope of the effort is almost incomprehensible, both for its sheer size and persistence on a low-lying peninsula, where the delineation between land and sea has always been somewhat unclear and is becoming less so.—
Amy Green,
Miami Herald,
9 Jan. 2026
Adjective
-
This is a major step forward in Japan’s long and cautious return to nuclear power and comes as the country braces for tight electricity supplies ahead of the summer peak.—
Kaif Shaikh,
Interesting Engineering,
21 Jan. 2026
-
Those looking for an elevated alternative to loose sweatpants, restrictive jeans, and tight leggings will appreciate their lightweight and airy feel.—
Michelle Baricevic,
Travel + Leisure,
21 Jan. 2026
Adjective
-
Opponents said McLean’s plan would cut down 17 acres of trees and add 7 acres of impervious surfaces, worsening the periodic flooding that’s already a concern.—
Don Stacom,
Hartford Courant,
23 Jan. 2026
-
The dressing room is more impervious to external influence than any other in European football.—
Sebastian Stafford-Bloor,
New York Times,
14 Jan. 2026
Adjective
-
Disco, Occasionally, the British superstar’s fourth studio album that’s been teased via a creeping, ongoing rollout with cryptic posters, a WhatsApp chat, listening sessions in indie record shops and a series of city residencies in place of a sprawling global tour.—
Jeff Benjamin,
Forbes.com,
23 Jan. 2026
-
The announcement of a new tour and album comes weeks after Styles teased devotees with posters, videos, a cryptic website and an intriguing song snippet starting in late December.—
Melissa Ruggieri,
USA Today,
22 Jan. 2026
Adjective
-
As satire, Next to Heaven is unintelligible, as though someone is universalizing their own hangups and then skewering them for clout.—
Literary Hub,
Literary Hub,
17 Dec. 2025
-
A number of individuals who were in that classroom told authorities that the gunman shouted an unintelligible statement and then began shooting students.—
Chris Spargo,
PEOPLE,
15 Dec. 2025
Adjective
-
The impermeable seed coat strategy generally helps survival of the species by making sure all of a season’s crop don’t germinate in the same year.—
Paul Cappiello,
Louisville Courier Journal,
21 Nov. 2025
-
The discovery could enable large-scale use of impermeable coatings once limited by graphene’s scalability issues.—
Aamir Khollam,
Interesting Engineering,
12 Nov. 2025
Cite this Entry
“Impenetrable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/impenetrable. Accessed 28 Jan. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
