" doubtlessness "

1: a state of mind in which one is free from doubt;

  * e.g., " ... with the doubtlessness of a man who never spent a moment in self-reflection, the president barreled down the road to disaster "

•  Synonyms : 

•  assurance,

•  assuredness,

•  certainty,

•  certitude,

•  cocksureness,

•  confidence,

•  conviction,

•  face,

•  positiveness,

•  satisfaction,

•  sureness,

•  surety

•  Antonyms : 

•  doubt,

•  incertitude,

•  nonconfidence,

•  uncertainty

1: having or showing a mind free from doubt;

  * e.g., " ... another one of his doubtless predictions that will never come true "

•  Synonyms : 

•  assured,

•  certain,

•  clear,

•  cocksure,

•  confident,

•  implicit,

•  positive,

•  sanguine,

•  sure

•  Antonyms : 

•  doubtful,

•  dubious,

•  uncertain,

•  unsure