Antonyms of adj climbable

2 senses of climbable

Sense 1
ascendable, ascendible, climbable -- (capable of being ascended)

INDIRECT (VIA scalable) -> unscalable, unclimbable -- (incapable of being ascended)

Sense 2
surmountable, climbable -- (capable of being surmounted)

INDIRECT (VIA passable) -> impassable, unpassable -- (incapable of being passed)

Similarity of adj climbable

2 senses of climbable

Sense 1
ascendable, ascendible, climbable -- (capable of being ascended)
       => scalable (vs. unscalable) -- (capable of being scaled; possible to scale; "the scalable slope of a mountain")

Sense 2
surmountable, climbable -- (capable of being surmounted)
       => passable (vs. impassable) -- (able to be passed or traversed or crossed; "the road is passable")