[chal.lenge] vb chal.lenged ; chal.leng.ing [ME chalengen to accuse, fr. OF chalengier, fr. L calumniari to accuse falsely, fr. calumnia calumny] vt (13c) 1: to demand as due or deserved: require "an event that ~s explanation"
2: to order to halt and prove identity "the sentry challenged the stranger"
3: to dispute esp. as being unjust, invalid, or outmoded: impugn "new data that ~s old assumptions"
4: to question formally the legality or legal qualifications of
5. a: to confront or defy boldly: dare b: to call out to duel or combat c: to invite into competition
6: to arouse or stimulate esp. by presenting with difficulties 7: to administer a physiological and esp. an immunologic challenge to (an organism or cell) ~ vi 1: to make or present a challenge
2: to take legal exception -- chal.leng.er n
[2]challenge n (14c) 1 a: a summons that is often threatening, provocative, stimulating, or inciting; specif: a summons to a duel to answer an affront b: an invitation to compete in a sport
2. a: a calling to account or into question: protest b: an exception taken to a juror before he is sworn c: a sentry's command to halt and prove identity d: a questioning of the right or validity of a vote or voter
3: a stimulating task or problem "looking for new ~s"
4: the process of provoking or testing physiological activity by exposure to a specific substance; esp: a test of immunity by exposure to an antigen