By extension, in general speech it's a lengthy, arduous or time-consuming undertaking.

It was not, however, until late in the afternoon that I fully succeeded in my arduous undertaking.

Creating this altarpiece assembled from many wood panels bonded together before painting was an arduous undertaking.

A marathon is a distance race of 42.195 km (26 miles 385 yards) and, by extension, in general speech a lengthy, arduous or time-consuming undertaking.

Thus they prepare themselves for long journeys or arduous undertakings.

At the time, an overland journey across the US was an arduous undertaking and could last many weeks.

"Well, do you know that you have got one of the most expensive and arduous undertakings before you that was ever conceived by man?"

He commenced this arduous undertaking after he had entered his seventieth year.

It was an arduous undertaking, in which all took part.

The main altar as well as the balusters are constructed of granite, obviously a quite arduous and painstaking undertaking.