A portmanteau of "flail" and "arm". To flarm is to swing one's arms about wildly in a spastic manner, usually as an expression of surprise, amazement, or joy.
Sasha flarmed with excitement at the news, knocking over a glass in the process.
The excess skin that hangs on the underside of the upper arm, typically found on older, oftentimes overweight people. Derived from "Flabby Arm" = Flarm
As a child, I used to enjoy shaking the flarm on my mother's arm and watch it wiggle like jello.