n. A prefix (turbo-), used in composition to designate a machine in which the motive energy is derived from a steam turbine either directly connected, or on the same revolving shaft as the element designated by the other word of the compound: as, a turbo-alternater, an alternating-current dynamo the armature of which is the prolongation of the axis of the steam turbine; a turbo-generator, a dynamo either for direct or alternating current, similarly directly driven. See cut at Curtis steam turbine.n. As a substantive: A pump or ventilator in which the impeller revolves as a turbine, or as a top, and drives the fluid which it is to displace by a centrifugal or rotary action.n. A direct-connected turbine-driven generator; an abbreviation of turbo-dynamo.n. The typical genus of the family Turbinidæ, formerly very extensive, now restricted to species with a regularly turbinated shell, rounded aperture, smooth beveled columellar lip, and a calcareous operculum with a central or subcentral nucleus.n. A shell of this genus.