The phrase "great challenge" means a difficult and important task or obstacle that requires a lot of effort and determination to overcome. Full definition
The greatest credit goes to students, families and teachers who are putting in the work and showing great determination and resolve, sometimes in the face of great challenge. (americaspromise.org)
As more resources become available only electronically, there will be an even greater challenge for academic libraries who wish to provide meaningful public access to their materials. (slaw.ca)
We work in many ways simultaneously because we are diverse we face greater challenges in defining ourselves, but our diversity is also our greatest strength. (abaforlawstudents.com)