Forget about not being able to work; getting out of bed was a major undertaking.

Even going out for the evening was a major undertaking.

Once that was done, getting everything back on-line would be a major undertaking.

For one thing, a house move is a major undertaking.

"We can't have any major undertaking in the house with it while it's being prepared."

What other possible reason could there be, for such a major undertaking?

The $36 million theater project, announced in March 2004, was the first major undertaking of the new district.

For a small group of no more than 35 members this was a major undertaking.

It has been a major undertaking for a small municipal museum.

But there was a reason for such a major undertaking.