impenetrable

adjective

(ˌ)im-ˈpe-nə-trə-bəl How to pronounce impenetrable (audio)
Definition of impenetrablenext
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 Cody erects impenetrable emotional walls around him that deny him from asking for help and creating community. — Randy Myers, Mercury News, 12 Aug. 2026 The pair will share the screen with Will Smith and AnnaSophia Robb, who play two FBI agents investigating a seemingly impossible murder within the impenetrable walls of a maximum-security prison. — Matt Grobar, Deadline, 7 Aug. 2026 There was a metal gate rolled out making the front portion of the plane an impenetrable fortress. — David Hookstead Outkick, FOXNews.com, 7 Aug. 2026 Instead, my trembling body was confronted by an impenetrable wall of rock. — Literary Hub, 6 Aug. 2026 See All Example Sentences for impenetrable
Recent Examples of Synonyms for impenetrable
  1. dense
  2. mysterious
  3. incomprehensible
  4. tight
  5. impervious
  6. cryptic
  7. unintelligible
  8. impermeable
Adjective
  • Autumn Joy Stonecrop Also called autumn joy sedum, this hardy, summer- and fall-flowering perennial is known for its succulent foliage and dense clusters of tiny pink flowers.
    — Alexandra Jones, The Spruce, 30 Aug. 2026
  • There was less consensus about the dust kicked up from the playa, which can be dense enough to cause whiteouts.
    — Henry Alford, New Yorker, 29 Aug. 2026
Definition of dense
Adjective
  • Add the mysterious departure of the younger Belichick and that only adds more to Craig’s plate.
    — Steven Johnson, Fort Worth Star-Telegram, 27 Aug. 2026
  • Elizabeth, less inclined to anatomize herself in writing, remains the more mysterious force.
    — Literary Hub, Literary Hub, 27 Aug. 2026
Definition of mysterious
Adjective
  • War of the Worlds fuses post-9/11 paranoia and the terror of parenting to create one of Spielberg’s most thrilling blockbusters with a dark, genuinely scary atmosphere of ordinary people being wiped out by incomprehensible tragedy.
    — Wesley Stenzel, Entertainment Weekly, 21 Aug. 2026
  • Farnaby’s character, a thickly-accented and mostly-incomprehensible farmer, was, of course, called Barry.
    — Alex Ritman, Variety, 7 Aug. 2026
Definition of incomprehensible
Adjective
  • Dow stood with three tattooed and shirtless jumpers, weaving white paracord through hooks in the canvas and cinching it tight.
    — M. R. O’Connor, New Yorker, 31 Aug. 2026
  • Given the tight timeframe before the election, Sher is seeking both temporary relief and an interim injunction in the petition to ensure eligible citizens are not disenfranchised while bureaucratic procedures are reviewed.
    — Natasha Mozgovaya, Sun Sentinel, 31 Aug. 2026
Definition of tight
Adjective
  • This brand makes impervious base layers with a chemical-free blend of nylon and lycra.
    — Olivia Young, Travel + Leisure, 13 Aug. 2026
  • To deal with the settling, Peters and his team developed flexible flooring lined with an impervious three-ply fabric.
    — Jennifer Tucker, The Conversation, 7 Aug. 2026
Definition of impervious
Adjective
  • McEwen offered a cryptic tease about what audiences can expect.
    — Naman Ramachandran, Variety, 28 Aug. 2026
  • But the ambassador retorts with evasion, keeping the language cryptic.
    — Andy Andersen, Vulture, 23 Aug. 2026
Definition of cryptic
Adjective
  • Incomplete, corrupted, untimely, or unintelligible Submissions or Submission Forms will be disqualified.
    — August 16, NPR, 16 Aug. 2026
  • When the surveillance footage resumes about an hour later, a man can be heard shouting, but the words are unintelligible, and a vehicle horn sounds.
    — Kansas City Star, Kansas City Star, 10 Aug. 2026
Definition of unintelligible
Adjective
  • State officials estimated the costs at $4,100 per acre of paved or impermeable surface for those that decide to help fund local stormwater projects, and said the costs for other options could be considerably higher.
    — Ian James, Los Angeles Times, 29 July 2026
  • Spain needed until the 106th minute to slip a Ferran Torres shot past the impermeable goalkeeping of Argentina’s Emiliano Martínez, whose championship-game record 11 saves proved one too few.
    — Jerry Brewer, New York Times, 20 July 2026
Definition of impermeable

Browse Nearby Words

impenetrability
impenetrable
impenitence
See all Nearby Words

Cite this Entry

“Impenetrable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/impenetrable. Accessed 1 Sep. 2026.

Copy Citation
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Is it 'nerve-racking' or 'nerve-wracking'?

What's the difference between 'fascism' and 'socialism'?

Why does English have so many silent letters?

7 Pairs of Commonly Confused Words
See More

Popular in Wordplay

See More

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of

Even More Words That Sound Like Insults But Aren't

Even More Bird Names that Sound Like Insults (and Sometimes Are)

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
skateboard-dog-hat
Wordmaxxing Slang Quiz Give your vocabulary a glow up by getting sendy w...
See All