’So, whether I am waiting for a hostile message, or an assignation, or a penitent remonstrance, or an impromptu wrestle with my friend Bounderby in the Lancashire manner — which would seem as likely as anything else in the present state of affairs — I’ll dine,’ said Mr. James Harthouse.
There are no more uses of "impromptu" in the book.
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In one picture, which seems like the most recent but still looks a few years dated, his dad has his arms around the two boys, and he’s squeezing them together for an impromptu photo.
Colleen Hoover -- Slammed
I hesitate for a split second, long enough to place the tune—Frank Sinatra, "New York, New York"—and say a prayer of thanks that the Pugs aren’t witness to my mom’s impromptu performance.