risibility

— Lady Anne was very angry, both at herself and the Count; nevertheless, his perfect simplicity and sincerity, and the nonchalance with which he spoke, amused her as much as it vexed her; and, as poor Georgiana, after various efforts to subdue her risibility, was constrained to laugh outright, the features of Lady Anne admitted the Chesterfieldian smile, and she exclaimed, "Really, Count, you are the drollest man in the world, and say the oddest things in the world."