impenetrable /im-penˈi-trə-bl/

1. Incapable of being penetrated
2. Impervious
3. Inscrutable
4. Occupying space exclusively (physics)

impenetrabilˈity noun

impenˈetrably adverb

• unemployment benefit
• unemployments
• unemptied
• unenchanted
• unenclosed
• unencumbered
• unendangered
• unendeared
• unending
• unendingly
• unendingness
• unendingnesses
• unendowed
• unendurable
• unendurably
• unenforceable
• unenforced
• unengaged
• un-English
• un-Englished
• unenjoyable
• unenlightened
• unenquiring
• unenriched
• unenslaved