›[C or U]a job, duty, or situation that is difficult because you must use a lot of effort, determination, and skill in order to be successful: accept/face/meet a challengeAfter significant losses last year, the company now faces the challenge of trying to repair its reputation with investors.be/pose/present a challengeThe weakness of the dollar could pose a challenge to the company's expansion plans.As a software developer he enjoys the challenge of working with cutting-edge technology.She was getting bored at work and felt she needed a new challenge.Finding time to do the work has proven a real challenge.a big/major/serious challenge
›[C]an invitation for someone to compete against you or for you to prove that you can achieve a particular goal: challenge from sbResponding to a challenge from dissident shareholders, the board approved a number of steps to enhance shareholder value.
›[C]an act of asking whether something is true or legal, or whether someone has the authority or right to do something: mount/launch a challenge againstUnions are planning to launch a legal challenge against the airline for changing the work schedules of 14,000 cabin crew.