- Definitions|2
- Thesaurus|1.9k
- Abbreviations|0
52 entries under implausible topic. ×
| hundred-to-one(doubtful, unlikely) | |
| iffy(doubtful, unlikely) | |
| impossible(extraordinary, strange, unreasonable, amazing, dubious) | |
| impracticable(useless, trivial, doubtful, insufficient, hopeless) | |
| incogitable(extraordinary, strange, amazing, unbelievable) | |
| insupposable(extraordinary, strange, unbelievable, improbable) | |
| mind-boggling(extraordinary, strange, amazing, unbelievable) | |
| not expected(expression, doubtful, unlikely) | |
| not likely(expression, unreasonable, doubtful, dubious, flimsy) | |
| outlandish(extraordinary, amazing, unbelievable, incredible) | |
| outside chance(expression, doubtful, unlikely) | |
| phony(extraordinary, strange, amazing, unbelievable) | |
| questionable(extraordinary, amazing, doubtful, unlikely) | |
| reachy(extraordinary, strange, unreasonable, dubious, unlikely) | |
| ridiculous(adjective, unbelievable, improbable) | |
| slim(adjective, weak, fine, thin, delicate) | |
| slim and none(expression, idiom, doubtful, unlikely) | |
| staggering(extraordinary, strange, amazing, unbelievable) | |
| suspect(extraordinary, unreasonable, amazing, dubious, unlikely) | |
| unheard of(expression, doubtful, unlikely) |
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| APA | Smart Define. (2016). unsubstantial thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/unsubstantial/thesaurus/synonyms |
| Chicago | Smart Define. 2016. "unsubstantial thesaurus" https://smartdefine.org/unsubstantial/thesaurus/synonyms (accessed September 23, 2026). |
| Harvard | Smart Define 2016, unsubstantial thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/unsubstantial/thesaurus/synonyms>. |
| MLA | Smart Define. "unsubstantial thesaurus" 30 March 2016. Web. 23 September 2026. <https://smartdefine.org/unsubstantial/thesaurus/synonyms> |