IMPENETRABILITY Scrabble 24 Words With Friends 28 Definition noun the quality of being impenetrable (by people or light or missiles etc.). — synonyms: imperviousness noun incomprehensibility by virtue of being too dense to understand. — synonyms: impenetrableness See all 1569 words you can make from IMPENETRABILITY → 15-letter words Words starting with I Words ending with Y ← Unscramble different letters