To fail to keep up with someone or something

To not be successful in achieving something

असफल रहना

English Usage: He fears that he will fall behind in his career if he doesn't improve his skills.

Hindi Usage: उसे डर है कि अगर वह अपने कौशल को नहीं सुधारता तो वह अपने करियर में असफल रह जाएगा।