1. in a crazy, wild, or eccentric manner; in a way that suggests mental instability or foolishness
Usage: informal; derived from the adjective 'loony'

Examples

• He was grinning loonily at the joke that no one else found funny.
• She danced loonily across the stage, flailing her arms without rhythm.
• The character spoke loonily, mixing nonsense with occasional bursts of clarity.
• He laughed loonily at his own pun, unable to contain his amusement.
• The old man waved loonily from his porch, greeting every passing car.