Todays word: challenge

challenge (DIFFICULT JOB)
noun [C or U]
(the situation of being faced with) something needing great mental or physical effort in order to be done successfully and which therefore tests a person's ability:
Finding a solution to this problem is one of the greatest challenges faced by scientists today.
You know me - I like a challenge.
It's going to be a difficult job but I'm sure she'll rise to the challenge.