The stout lady occasionally turned her head squarely around and surveyed Anne through her eyeglasses until Anne, acutely sensitive of being so scrutinized, felt that she must scream aloud; and the white-lace girl kept talking audibly to her next neighbor about the "country bumpkins" and "rustic belles" in the audience, languidly anticipating "such fun" from the displays of local talent on the program.
But that night, when Marilla went to bed, acutely and miserably conscious that the little gable room at the end of the hall was untenanted by any vivid young life and unstirred by any soft breathing, she buried her face in her pillow, and wept for her girl in a passion of sobs that appalled her when she grew calm enough to reflect how very wicked it must be to take on so about a sinful fellow creature.
There are no more uses of "acute" in the book.
To see samples from other sources, click a word sense below: as in: acute pain
sharp (a severely negative event) -- often with a rapid onset