swing, brandish, flourish
掄 centers on moving something through the air with a sweeping motion: swinging, brandishing, or flourishing an object.
掄 combines 扌 (hand) with 侖, which likely contributes the sound. The hand radical suggests an action performed with the hand, such as swinging or brandishing.
The hand radical 扌 beside 侖 suggests a hand swinging something. Picture a hand gripping a tool and sweeping it through the air in a flourish.
For ロン, imagine swinging a long ribbon through the air: long -> ロン, and the ribbon flourishes with each swing.