LANDSPOUT

A landspout is a slang-term coined by meteorologist Howard B. Bluestein in the early 1980s for a kind of tornado not associated with the mesocyclone of a thunderstorm. The Glossary of Meteorology defines a a landspout as "Colloquial expression describing tornadoes occurring with a parent cloud in its growth stage and with its vorticity originating in the boundary layer.The parent cloud does not contain a preexisting midlevel mesocyclone. The landspout was so named because it looks like a weak Florida Keys waterspout over land. See nonsupercell tornado."
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[Slang], a tornado that does not arise from organized storm-scale rotation and therefore is not associated with a wall cloud (visually) or a mesocyclone (on radar). Landspouts typically are observed beneath Cbs or towering cumulus clouds (often as no more than a dust whirl ), and essentially are the land-based equivalents of waterspouts .