impenetrable /im-penˈi-trə-bl/

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

impenetrabilˈity noun

• incarvillea
• incarvilleas
• in case
• incase
• incased
• incasement
• incasements
• incases
• in case to
• in cash
• incasing
• incatenation
• incatenations
• incaution
• incautions
• incautious
• incautiously
• incautiousness
• incautiousnesses
• incave
• incaved
• incaves
• incavi
• incaving
• incavo