challenge · n
challenge (DISAGREEMENT)
C2 an expression of disagreement with ideas, rules, or someone's authority
Dictionary examples:
a challenge to the authority of the President (41.7)
challenge (DIFFICULT)
B1 something that is difficult and that tests someone's ability or determination
Dictionary examples:
Keeping a straight face during a boring meeting is a real challenge. (0.0)
The challenge of staying awake in history class tests my determination. (0.0)
Avoiding social media for a day is a modern challenge. (0.0)
You know me - I like a challenge. (25.4)
It's going to be a difficult job but I'm sure she'll rise to the challenge. (40.8)
Finding a solution to this problem is one of the greatest challenges faced by scientists today. (41.7)