| 例句 |
impregnableadjective incapable of being defeated, overcome, or subduedan impregnable fortress that had foiled one invader after another over the centuries bulletproof, indomitable, insuperable, insurmountable, invincible, invulnerable, unbeatable, unconquerable, unstoppable inviolable, unassailable, unbreachable, untouchablearmored, defended, guarded, protected, safe, safeguarded, secure, shieldedunbeaten, unbowed, unconquered, undefeated, unsubdued superable, surmountable, vincible, vulnerable exposed, imperiled(or imperilled), insecure, liable, open, susceptible, unguarded, unprotected, unsafedefenseless, helpless, powerless, weak impossible to get through or intothe castle's supposedly impregnable walls impassable(also impassible), impenetrable, impermeable, impervious close, compact, dense, thick, tightcompressed, condensedsturdy, substantial, toughfirm, frozen, hard, solid, stiffinflexible, rigid, unbending, unyielding negotiable, passable, penetrable, permeable soft, squishybendable, elastic, flexible, giving, malleable, pliable, yieldingabsorbent, porous in the 15th century |