interrogation point

Also called interrogation mark.

Origin of interrogation point

First recorded in 1590–1600

Why, Mephisto has some pretty good traits; but Alexander Pope is as crooked as an interrogation-point, inside and out.

Little Journeys to the Homes of the Great - Volume 14 |Elbert Hubbard
"A stranger to me, of course," said Locker, his whole form twisting itself into an interrogation-point.

The Captain's Toll-Gate |Frank R. Stockton
Another of our common wild flowers, which I always look at with an interrogation-point in my mind, is the wild ginger.

Riverby |John Burroughs
Each star that blinked down at him as he rode in answer to a night-call seemed an interrogation-point asking, How do I exist?

A History of Science, Volume 3(of 5) |Henry Smith Williams

So to make sure, whenever he wished an interrogation-point he said "question" at the end of almost every sentence.

Electricity and Magnetism |Elisha Gray