Laboriously is how you do something when it takes a lot of time and effort: slowly, heavily, and often with the effort showing. He climbed the stairs laboriously — each step costs him. She copied the names laboriously, one by one. Like laborious, it can hint that the work looks stiff rather than easy, as if the person is pushing the thing uphill. It is a slightly formal adverb; everyday English may just say “with a lot of effort” or “the hard way”. Use it of the action, not of the person.