What is "upending"

Usage examples of "upending".

His left hand flew up toward his cap, catching the corner of the board and upending it with a smack.

He beheld her pale body and hair spring and turn over, and then the upending of something that curved up like a bow against the shining sky, flickering a fan of silvered paper upon its utmost end.

He held it steady in preparation for upending the contents into the tank.

In Derendorf Matern makes room on the running board for a bilious watchmaker, who might also be a professor, by upending his barracks bag.