Literally, in order for a vortex to be classified as a tornado, it must be in contact with the ground and the cloud base. Weather scientists haven't found it so simple in practice, however, to classify and define tornadoes (per this essay by Doswell).
Bikini Island, 2015. Credit: Emlyn Hughes. (Phys.org)âA team of researchers from Columbia University in New York has found that all of the Marshall Islands involved in nuclear tests by the U.S. are now habitable, except for Bikini Atoll.
The noun BIKINI has 2 senses: 1. an atoll in the Marshall Islands; formerly used by the United States as a site for testing nuclear weapons. 2. a woman's very brief bathing suit. Familiarity information: BIKINI used as a noun is rare.