mainchallenge
nounUK /ˌmeɪn ˈtʃælɪndʒ/
US /ˌmeɪn ˈtʃælɪndʒ/
The main challenge is the biggest hard thing you have to do.
The main challenge of the game is finding the hidden key.
OTHER MEANINGS
2. The most important problem a team must solve first.
Our main challenge is finishing the project before Friday.
3. The hardest part of a contest or activity.
For many runners, the main challenge is the steep hill at the end.
4. The biggest thing that makes something difficult to do.
The main challenge of learning to swim is not being afraid of the water.