challenge

Noun

• a demand by a sentry for a password or identification

• a formal objection to the selection of a particular person as a juror

• questioning a statement and demanding an explanation
  • his challenge of the assumption that Japan is still our enemy
    

• a call to engage in a contest or fight

• a demanding or stimulating situation
  • they reacted irrationally to the challenge of Russian power
    

Verb

• raise a formal objection in a court of law

• ask for identification
  • The illegal immigrant was challenged by the border guard
    

• issue a challenge to
  • Fischer challenged Spassky to a match
    

• take exception to
  • She challenged his claims
    

Related words

• Synonyms: 
  take exception , dispute , gainsay