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”[…]

Source: wiktionary

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

Source: wiktionary

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.

Source: wiktionary

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.”

Source: wiktionary