2. Anything which whirls around, or in which persons or things are whirled about, as a frame with seats or wooden horses. With a whirligig of jubilant mosquitoes spinning about each head. (G. W. Cable)
4. (Science: zoology) Any one of numerous species of beetles belonging to Gyrinus and allied genera. The body is firm, oval or boatlike in form, and usually dark coloured with a bronzelike luster. These beetles live mostly on the surface of water, and move about with great celerity in a gyrating, or circular, manner, but they are also able to dive and swim rapidly. The larva is aquatic.
Origin: Whirl _ gig.