Whirligig

n. [From whirl and gig. See GIG.] 1. A child's toy, spun or whirled around like a wheel upon an axis, or like a top. Johnson.

2Sense 2. An instrument for punishing petty offenders, used especially in the army, being a kind of wooden cage turning on a pivot, in which the offender was whirled round with great velocity. [Obs.]

3Sense 3. (Entom.) An insect of the genus Gyrinus, usually of an oval form and black color, with a brilliant bronze metallic luster, which lives on the surface of water, and moves about with great celerity in a gyrating or circular manner, the most common species being G. natator, popularly called weaver, in America, from its motions. Baird.

a. Fickle; giddy.