impenetrable

[ im-pen-i-truh-buhl ]

adjective

1. not penetrable; that cannot be penetrated, pierced, entered, etc.
2. inaccessible to ideas, influences, etc.
3. incapable of being understood; inscrutable; unfathomable:

   an impenetrable mystery.

   Synonyms: hidden, obscure, mysterious, incomprehensible

   Antonyms: lucid, clear

4. Physics. possessing impenetrability.

impenetrable

/ ɪmˈpɛnɪtrəbəl /

adjective

1. incapable of being pierced through or penetrated

   an impenetrable forest

2. incapable of being understood; incomprehensible

   impenetrable jargon

3. incapable of being seen through

   impenetrable gloom

4. not susceptible to ideas, influence, etc

   impenetrable ignorance

5. physics (of a body) incapable of occupying the same space as another body

Derived Forms

• imˈpenetrableness, noun
• imˌpenetraˈbility, noun
• imˈpenetrably, adverb

Other Words From

• im·pene·tra·ble·ness noun
• im·pene·tra·bly adverb

Word History and Origins

Origin of impenetrable¹

1425–75; late Middle English impenetrabel < Latin impenetrābilis. See im- ², penetrable

Example Sentences

Importantly, the kink in cis fats means they cannot be tightly packed -- a positive feature for avoiding impenetrable clogs.

From Science Daily

A separate thread in the series follows the McConville children over the decades, as they fight an impenetrable code of silence to uncover the truth about their mother.

From Los Angeles Times

South Korea’s frontier with the North is an almost impenetrable barrier, the heavily mined and fortified Demilitarized Zone.

From BBC

Partly journalism can’t rise to the occasion because we will never shake off our obsession with horse races and novelty, and partly journalism can’t rise to the occasion because we live in a world of such impenetrable bubbles that even were an October surprise to burst through the sound and light show, the people who most need to see and hear and believe it never would.

From Slate

Roberts' law clerks must have put in for disability pay after the time they spent paging through the impenetrable gibberish of former Supreme Court justices and other federal judges, none of whom, it should be noted, ever located the paragraph or sentence in the Constitution where the word “immunity” is found alongside the words “president” or “presidential.”

From Salon

Related Words

• arcane
• baffling
• inexplicable
• inscrutable
• mysterious
• unaccountable
• unfathomable
• unintelligible