The airship is virtually impervious to automatic rifle and mortar fire: ordnance passes through the envelope without causing critical helium loss.

As an environment for military conflict, Afghanistan is virtually impervious to American power.

In an interview with New Orleans magazine in 1997, she insisted that the beef business was virtually impervious to health trends.

Teak is protected by its own natural oils that migrate to the surface of the wood and make the wood virtually impervious to water.

But Microsoft's lawyers will have to find grounds in law or precedent because the judge's findings of fact are virtually impervious to appeal.

They drip in gold and pearls but appear virtually impervious to movement.

Whoever created it made it virtually impervious to the normal vaccines we use today.

His robot body is virtually impervious to harm.

As a result, he is virtually impervious to all but devastating wounds.

In terms of outside attack, they are virtually impervious.