Definition of "challenge" []

• A call to engage in a contest, fight, or competition: a challenge to a duel. (noun)
• An act or statement of defiance; a call to confrontation: a challenge to the government's authority. (noun)
• A demand for explanation or justification; a calling into question: a challenge to a theory. (noun)
• A sentry's call to an unknown party for proper identification. (noun)
• A test of one's abilities or resources in a demanding but stimulating undertaking: a career that offers a challenge. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Now we are in the process of restructuring ISI� The present leadership of ISI is very clear that this challenge is our challenge� if there are opinions that need to be expressed, they should not be done through the media."
• "I would make it a timed skill challenge, in which the players have to score [Number of players x 2] successes in three rounds (this is close enough to a complexity = [number of players] skill challenge*)."
• "City beat Bayern with goals from David Silva in the 37th minute and Yaya Touré seven minutes after the break confirming the win, but Mancini must now lift his squad for the lesser European club competition while maintaining a title challenge in which they lead United by five points."