difficult; arduous; hard

Bringing up a baby is hard work.

And I know you didn't do this just to win an election. And I know you didn't do it for me. You did it because you understand the enormity of the task that lies ahead. For even as we celebrate tonight, we know the challenges that tomorrow will bring are the greatest of our lifetime: two wars, a planet in peril, the worst financial crisis in a century.

His courage will carry him through this difficult job.

The old lady climbed the stairs with difficulty.

I think that, in tough times, you can cry as much as you want.