- Definitions|2
- Thesaurus|1.5k
- Abbreviations|0
49 entries under rigid topic. ×
| rocklike(adjective, firm, stiff) | |
| set(adjective, hard, tough, firm, solid) | |
| durable(adjective, firm, stiff) | |
| fine-grained(hard, solid) | |
| indurate(adjective, set, strong, hard, firm) | |
| inelastic(hard, solid) | |
| iron(adjective, set, strong, hard, firm) | |
| refractory(hard, solid) | |
| sturdy(hard, solid) |
For more, visit
Impenetrable on
Power Thesaurus
| APA | Smart Define. (2015). impenetrable thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/impenetrable/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "impenetrable thesaurus" https://smartdefine.org/impenetrable/thesaurus/synonyms (accessed September 26, 2026). |
| Harvard | Smart Define 2015, impenetrable thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/impenetrable/thesaurus/synonyms>. |
| MLA | Smart Define. "impenetrable thesaurus" 10 April 2015. Web. 26 September 2026. <https://smartdefine.org/impenetrable/thesaurus/synonyms> |