Nonplussation

And now a spectacle presented itself which set the old professor’s wits altogether abroad, […] gazing blankly at the strangers, with features expressive of amazement, strong curiosity, and complete “nonplussation”[…]

[…] arrives at the height of "nonplussation" when his father meets him and his fashionable affianced, and says, "my son, vot young gal is that?"

They stared after it with a gape of utter nonplussation “ And my internal spirit cut a caper,” as the poet sublimely says, for I could not have slept at night if those crows had enjoyed their disreputable meal.

If she decided to have the baby, could she pass it off as his? He was presumably familiar with the standard human gestation period. “I'm pregnant,” she said. A period of nonplussation “I only took the test last night. I haven't seen a doctor. But I'm late and it was positive. Faintly positive, but ...” “Huh.”