- Definitions|2
- Thesaurus|1.5k
- Abbreviations|0
65 entries under obscure topic. ×
| unfathomable(adjective, hard, knowledge, difficult) | |
| incomprehensible(adjective, knowledge, solid, dark) | |
| inscrutable(adjective, knowledge, blank, sophisticated) | |
| arcane(adjective, solid, strange, doubtful) | |
| unintelligible(adjective, knowledge, solid, dark) | |
| mysterious(adjective, solid, strange, secret) | |
| enigmatic(adjective, difficult, solid, strange) | |
| deep(adjective, set, solid, heavy) | |
| inexplicable(adjective, solid, dark, strange) | |
| mystic(adjective, solid, dark, superior) | |
| occult(adjective, dark, superior, strange) | |
| murky(adjective, solid, dark, gloomy) | |
| unknowable(adjective, solid, dark, superior) | |
| abstruse(adjective, difficult, strange, deep) | |
| puzzling(adjective, strange, sophisticated, complicated) | |
| unaccountable(adjective, solid, strange, doubtful) | |
| baffling(adjective, solid, deep, mysterious) | |
| cryptic(adjective, strange, sophisticated, complicated) | |
| dark(adjective, feature, mysterious, hidden) | |
| hidden(adjective, difficult, solid, dark) |
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| APA | Smart Define. (2015). impenetrable thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/impenetrable/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "impenetrable thesaurus" https://smartdefine.org/impenetrable/thesaurus/synonyms (accessed September 27, 2026). |
| Harvard | Smart Define 2015, impenetrable thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/impenetrable/thesaurus/synonyms>. |
| MLA | Smart Define. "impenetrable thesaurus" 10 April 2015. Web. 27 September 2026. <https://smartdefine.org/impenetrable/thesaurus/synonyms> |