Antonyms of adj impregnable

3 senses of impregnable

Sense 1
impregnable, inviolable, secure, strong, unassailable, unattackable -- (immune to attack; incapable of being tampered with; "an impregnable fortress"; "fortifications that made the frontier inviolable"; "a secure telephone connection")

INDIRECT (VIA invulnerable) -> vulnerable -- (susceptible to attack; "a vulnerable bridge")

Sense 2
conceptive, impregnable -- (capable of conceiving)

INDIRECT (VIA fertile) -> sterile, unfertile, infertile -- (incapable of reproducing; "an infertile couple")

Sense 3
impregnable, inexpugnable -- (incapable of being overcome, challenged or refuted; "an impregnable argument"; "impregnable self-confidence")

INDIRECT (VIA unconquerable) -> conquerable -- (subject to being conquered or overcome; "knew her fears were ultimately conquerable")

Similarity of adj impregnable

3 senses of impregnable

Sense 1
impregnable, inviolable, secure, strong, unassailable, unattackable -- (immune to attack; incapable of being tampered with; "an impregnable fortress"; "fortifications that made the frontier inviolable"; "a secure telephone connection")
       => invulnerable (vs. vulnerable) -- (immune to attack; impregnable; "gunners raked the beach from invulnerable positions on the cliffs")

Sense 2
conceptive, impregnable -- (capable of conceiving)
       => fertile (vs. sterile) -- (capable of reproducing)

Sense 3
impregnable, inexpugnable -- (incapable of being overcome, challenged or refuted; "an impregnable argument"; "impregnable self-confidence")
       => unconquerable (vs. conquerable) -- (not capable of being conquered or vanquished or overcome; "a tribute to his courage...and his unconquerable will"- R.E.Danielson; "faced unconquerable difficulties")