For no reason that was clear to Babbitt, heaviness was over them and they spoke laboriously and unwillingly.
Then Babbitt saw Professor Pumphrey laboriously crawling up hill, afoot, Staring owlishly at the revelers.
…and salesman of insurance—broken, silent, gray; a mystery, reputed to have been a "crack" real-estate man with a firm of his own in haughty Brooklyn; Chester Kirby Laylock, resident salesman out at the Glen Oriole acreage development—an enthusiastic person with a silky mustache and much family; Miss Theresa McGoun, the swift and rather pretty stenographer; Miss Wilberta Bannigan, the thick, slow, laborious accountant and file-clerk; and four freelance part-time commission salesmen.
"At this abundant harvest-time of all the year," Dr. Drew chanted, "when, though stormy the sky and laborious the path to the drudging wayfarer, yet the hovering and bodiless spirit swoops back o’er all the labors and desires of the past twelve months, oh, then it seems to me there sounds behind all our apparent failures the golden chorus of greeting from those passed happily on; and lo! on the dim horizon we see behind dolorous clouds the mighty mass of mountains—mountains of melody,…
There are no more uses of "laborious" in the book.