Mr. Guppy, who has an inquiring mind in matters of evidence and who has been suffering severely from the lassitude of the long vacation, takes that interest in the case that he enters on a regular crossexamination of the witness, which is found so interesting by the ladies that Mrs. Snagsby politely invites him to step upstairs and drink a cup of tea, if he will excuse the disarranged state of the tea-table, consequent on their previous exertions.
There are no more uses of "lassitude" in the book.
Show samples from other sources
They did not go hunting at all that night, but stayed near the den and rested, The next morning dawned fine and warm, and a general air of contented lassitude seemed to overcome all three.
Farley Mowat -- Never Cry Wolf
In every sense of the word having experienced rebirth, she possessed some of the lassitude and, as a matter of fact, a great deal of the helplessness of a newborn child.