impassable

/ɪmˈpæsəbəl/

Other forms: impassably

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.

Definitions of impassable

1. adjective

   incapable of being passed
   synonyms: unpassable

   unclimbable, unsurmountable

   incapable of being surmounted or climbed

   unnavigable

   incapable of being navigated

   untraversable

   incapable of being traversed

   antonyms:

   passable

   able to be passed or traversed or crossed

   navigable

   able to be sailed on or through safely

   negotiable

   capable of being passed or negotiated

   climbable, surmountable

   capable of being surmounted

   travelable, traversable

   capable of being traversed