" improbability "

1: as in unlikelihood, unlikeliness;

•  Synonyms : 

•  unlikelihood,

•  unlikeliness,

•  doubtfulness,

•  dubiousness,

•  impracticability,

•  impracticality,

•  implausibility,

•  incredibility,

•  incredibleness

•  Antonyms : 

•  liability,

•  likelihood,

•  probability,

•  credibility,

•  plausibility,

•  plausibleness,

•  feasibility,

•  feasibleness,

•  possibility,

•  potentiality,

•  reasonability,

•  reasonableness,

•  viability

1: not likely to be true or to occur;

  * e.g., " ... it seems improbable that the two writers never met since they traveled in the same social circles "

•  Synonyms : 

•  doubtful,

•  dubious,

•  far-fetched,

•  flimsy,

•  questionable,

•  unapt,

•  unlikely

•  Antonyms : 

•  likely,

•  probable