What does "impenetrably" mean?

In an impenetrable manner or state; imperviously.

What is a synonym for "impenetrably"?

Common synonyms include: hermetically, indestructibly, inscrutably.

adv

adv ·Rare ·Advanced level

Adverb

1
In an impenetrable manner or state; imperviously.
"Far otherwise the inviolable Saints, In cubick phalanx firm, advanced entire, Invulnerable, impenetrably armed;"

"Far otherwise the inviolable Saints, In cubick phalanx firm, advanced entire, Invulnerable, impenetrably armed;"

From impenetrable + -ly.