KanjiJLPT N1
Brandish

brandish, wave, wag, swing, shake

Mnemonic

A royal hand wearing a crown ring thrusts out of a speeding car sunroof to brandish a massive sword. The blade swings wildly, sending sparks off lampposts and scattering everyone on the street.
Additional thoughts
Picture the absurdity: a crowned hand poking out of a car roof, brandishing a sword like a mad king on a joyride. The scattering pedestrians reinforce the kanji's extended sense of dispersing outward.
Quick recall
A hand with a crown ring bursts from a car to brandish a sword wildly.

Details

The keyword for 揮 is brandish. This kanji conveys the idea of wielding or swinging something forcefully, as one would brandish a weapon or wave a commander's baton. It extends to the sense of directing or commanding, as in conducting an orchestra or exercising authority. The character also carries the meaning of scattering or spreading outward, as the motion of brandishing naturally disperses energy in all directions.
On'yomi
Kun'yomi
ふる.う