impregnably

== English == === Etymology === From impregnable +‎ -ly. === Adverb === impregnably (comparative more impregnably, superlative most impregnably) In an impregnable manner; so as to defy attack. === References === William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “impregnably”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.