13
unusual(adjective, obscure, strange, exceptional, marvelous)
12
strange(adjective, excellent, obscure, extraordinary, unusual)
12
unknown(adjective, knowledge, obscure, strange, mysterious)
11
exceptional(adjective, obscure, irregular, unique)
11
extraordinary(adjective, excellent, unusual, strange, superb)
10
rare(adjective, obscure, extraordinary, strange, special)
10
unprecedented(adjective, obscure, exceptional, original, unique)
9
nameless(adjective, knowledge, obscure, strange, unknown)
9
unfamiliar(adjective, obscure, strange, exceptional, marvelous)
8
singular(adjective, obscure, unique)
7
obscure(adjective, knowledge, strange, unknown, unfamiliar)
7
odd(adjective, excellent, new, exceptional, marvelous)
7
outlandish(adjective, obscure, strange, unique, bizarre)
7
peculiar(adjective, excellent, strange, exceptional, marvelous)
7
remarkable(adjective, excellent, extraordinary, unusual, strange)
7
unbelievable(adjective, obscure, extraordinary, strange, doubtful)
7
uncommon(adjective, excellent, strange, exceptional, marvelous)
7
unique
7
unsung(adjective, obscure, new, remote, unknown)
6
bizarre
<1234510>
11 years ago|5.5k views|share |citing 
APASmart Define. (2015). unheard-of thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/unheard-of/thesaurus/synonyms
ChicagoSmart Define. 2015. "unheard-of thesaurus" https://smartdefine.org/unheard-of/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, unheard-of thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/unheard-of/thesaurus/synonyms>.
MLASmart Define. "unheard-of thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/unheard-of/thesaurus/synonyms>