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Synonyms

impassable

American  
[im-pas-uh-buhl, -pah-suh-] / ɪmˈpæs ə bəl, -ˈpɑ sə- /

adjective

  1. not passable; not allowing passage over, through, along, etc..

    Heavy snow made the roads impassable.

  2. unable to be surmounted.

    an impassable obstacle to further negotiations.

  3. (of currency) unable to be circulated.

    He tore the bill in half, making it impassable.


impassable British  
/ ɪmˈpɑːsəbəl /

adjective

  1. (of terrain, roads, etc) not able to be travelled through or over

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • impassability noun
  • impassableness noun
  • impassably adverb

Etymology

Origin of impassable

First recorded in 1560–70; im- 2 + passable

Explanation

Whether it’s a road, a barrier, a river, or an abyss, if you can’t travel through or over it, you can describe it as impassable. When you break apart the word impassable, it’s pretty easy to figure out what it means. The im- prefix, a variant of in-, may be familiar to you as a way to say “not.” And passable is likely pretty familiar too, referring to something that can be crossed. When you combine those parts you get something that you can’t navigate. Impassable is usually used in a literal sense, referring to things that you can’t travel through — like side streets after a major snow storm.

Keep Reading on Vocabulary.com

Vocabulary lists containing impassable

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Also check the weather; most roads in the monument are dirt or gravel and can become impassable in rain.

From Los Angeles Times • Apr. 10, 2026

Amazon plans 200 rural hubs covering 13,000 ZIP Codes across 1.2 million square miles, facing challenges like impassable roads.

From The Wall Street Journal • Mar. 22, 2026

Rubaya sits on steep hillsides carved by deep ravines with dirt roads, often impassable during the rainy season, winding between unstable slopes.

From Barron's • Feb. 1, 2026

The recent storms have also closed roads throughout the park, covering paved roads in debris and making them impassable, according to a National Park Service news release.

From Los Angeles Times • Dec. 12, 2025

It was twenty miles from the bridge to Beaverville and that road could be as impassable as the road between the bridge and the campground.

From "Earthquake Terror" by Peg Kehret