All 4 Uses of

laborious

in

Moby Dick

The ship's company being reduced to but a handful, the captain called upon the Islanders to assist him in the laborious business of heaving down the ship to stop the leak.†
Chpt 52-54

laborious = difficult

But you must be a thorough whaleman, to see these sights; and not only that, but if you wish to return to such a sight again, you must be sure and take the exact intersecting latitude and longitude of your first stand-point, else so chance-like are such observations of the hills, that your precise, previous stand-point would require a laborious re-discovery; like the Soloma Islands, which still remain incognita, though once high-ruffed Mendanna trod them and old Figuera chronicled them.†
Chpt 55-57

For that business is an exceedingly laborious one; is not very soon completed; and requires all hands to set about it.†
Chpt 64-66 *

His spout was short, slow, and laborious; coming forth with a choking sort of gush, and spending itself in torn shreds, followed by strange subterranean commotions in him, which seemed to have egress at his other buried extremity, causing the waters behind him to upbubble.†
Chpt 79-81

Definition:

difficult (requiring hard work)