challenges

Noun

• a demanding or stimulating situation
• a call to engage in a contest or fight
• questioning a statement and demanding an explanation
• a formal objection to the selection of a particular person as a juror
• a demand by a sentry for a password or identification
• plural of challenge

Verb

• take exception to
• issue a challenge to
• ask for identification
• raise a formal objection in a court of law
• third-person singular simple present indicative of challenge

Synonyms

challenge, dispute, gainsay, take exception