A Lomcovák (or incorrectly spelled Lomcevak) is a family of extreme aerobatic maneuvers where the aircraft, with almost no forward speed, rotates on chosen axes[1] due to the gyroscopic precession and torque of the rotating propeller.
[2] The word originates from a quote by the Czechoslovak aerobatic pilot Ladislav Bezák's mechanic at the 1958 air show in Brno, Czechoslovakia.
When asked by journalists what Bezák's tumble maneuvers were, he jokingly called them Lomcovaks explaining it means headache.
The etymology origin is in Lomit which means "to diffract; to divide; braking (rod)," most likely a reference to the stick manipulation during the manoeuvre.
In the 1940s Czech aerobatic pilots called this a Talířek which means a small saucer, after the horizontal rotary movement of the aircraft.