impregnable /im-pregˈnə-bl/

1. That cannot be captured, broken into or taken by force
2. Which cannot be overcome, unassailable

impregnabilˈity noun

impregˈnably adverb

• fanlight
• fanlights
• fan mail
• fan mails
• fanned
• fannel
• fannell
• fannells
• fannels
• fanner
• fanners
• fannies
• fanning
• fannings
• fanny
• fanny about
• Fanny Adams
• fanny around
• fanny pack
• fanny packs
• fanon
• fanons
• fan out
• fan oven
• fan ovens