impassable

adjective

im·​pass·​able (ˌ)im-ˈpa-sə-bəl 

variants or less commonly impassible

: incapable of being passed, traveled, crossed, or surmounted

impassability

(ˌ)im-ˌpa-sə-ˈbi-lə-tē 

noun

impassableness

(ˌ)im-ˈpa-sə-bəl-nəs 

noun

impassably

(ˌ)im-ˈpa-sə-blē 

adverb

Synonyms of impassable

• dense
• close
• impervious
• impenetrable
• impermeable
• impregnable
• frozen
• thick

Examples of impassable in a Sentence

The roads were made impassable by the flood.

the road was impassable until snowplows cleared it

Recent Examples on the Web

There are dozens of Chinook populations across hundreds of rivers from California to Alaska, each facing unique challenges, such as impassable dams, overfishing and urban development. —Kelso Harper, Scientific American, 16 Dec. 2025

Nulla tenaci invia est via (For the tenacious, no road is impassable). —Robert Ross, Robb Report, 12 Dec. 2025

The National Park Service advised visitors to be aware that unpaved roads may be impassable due to storm damage and to be prepared for self-rescue when traveling on backcountry roads. —Julia Jacobo, ABC News, 10 Dec. 2025

Hazardous travel conditions are anticipated, with warnings noting that roads, bridges and overpasses may become slick or impassable, and widespread blowing snow could trigger whiteout. —Anna Skinner, MSNBC Newsweek, 9 Dec. 2025

Word History

First Known Use

1562, in the meaning defined above

Rhymes for impassable

• passable
• impassible
• irascible
• unsurpassable

Kids Definition

impassable

adjective

im·​pass·​able (ˈ)im-ˈpas-ə-bəl 

: impossible to pass, cross, or travel over

roads made impassable by the hurricane

impassability

(ˌ)im-ˌpas-ə-ˈbil-ət-ē 

noun