Definition of "whirligig"

Anything that whirls or spins around, such as a toy top or a merry-go-round.  examples

A device incorporating spinning, wind-driven propellers or pinwheels, used as whimsical outdoor decoration in a garden or on a porch.  examples

A whirligig beetle.  examples

(historical) A device for punishing prisoners, comprising a wooden cage that rapidly spins around to induce nausea.