Synonyms|713Antonyms|152|Broader|9Narrower|8Related|663
2
overweight
2
past comprehension
2
rank(dense, profuse)
2
sealed(adjective, fast, short, unaffected, unyielding)
2
secret(adjective, obscure, dark, superior, strange)
2
secure
2
serried
2
smoky(adjective, dark, gloomy, dirty, dreary)
2
solidified(adjective, set, hard, tough, solid)
2
sonorous
2
stiff(adjective, set, hard, tough, firm)
2
supernatural(adjective, obscure, dark, mysterious, spiritual)
2
unapproachable(unaffected, unyielding, unbending, resistant, unreceptive)
2
unattackable
2
unknown(obscure, dark, superior, strange, mysterious)
2
unpierceable(unaffected, unyielding, unbending, resistant, unreceptive)
2
unreadable(incoherent, unfathomable, incomprehensible, enigmatic, inarticulate)
2
unseen(adjective, hidden, latency implication)
2
unsusceptible(adjective, hard, unfeeling, unsympathetic, hardened)
2
viscid
For more, visit Impenetrable on Power Thesaurus
11 years ago|15k views|share |citing 
APASmart Define. (2015). impenetrable thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/impenetrable/thesaurus/synonyms
ChicagoSmart Define. 2015. "impenetrable thesaurus" https://smartdefine.org/impenetrable/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, impenetrable thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/impenetrable/thesaurus/synonyms>.
MLASmart Define. "impenetrable thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/impenetrable/thesaurus/synonyms>