" falsehood "

1: a false idea or belief;

  * e.g., " ... the possibility of a perpetual motion machine is one falsehood that has been disproved by modern physics "

•  Synonyms : 

•  delusion,

•  error,

•  fallacy,

•  falsity,

•  hallucination,

•  illusion,

•  misbelief,

•  misconception,

•  myth,

•  old wives' tale,

•  untruth

•  Antonyms : 

•  truth,

•  verity

2: a statement known by its maker to be untrue and made in order to deceive;

  * e.g., " ... several falsehoods in the witness's testimony that may be grounds for perjury "

•  Synonyms : 

•  fable,

•  fabrication,

•  fairy tale,

•  falsity,

•  fib,

•  lie,

•  mendacity,

•  prevarication,

•  story,

•  tale,

•  taradiddle,

•  untruth,

•  whopper

•  Antonyms : 

•  truth

3: the quality or state of being false;

  * e.g., " ... scientists eventually demonstrated the falsehood of the claim that prehistoric fish did not evolve lungs and legs "

•  Synonyms : 

•  erroneousness,

•  fallaciousness,

•  fallacy,

•  falseness,

•  falsity,

•  untruth

•  Antonyms : 

•  truth,

•  verity