[′ver·ē·ə·bəl ¦dī‚ōd ′fəŋk·shən ‚jen·ə‚rād·ər] (electronics) An improvement of a diode function generator in which fully adjustable potentiometers are used for breakpoint and slope resistances, permitting the programming of analytic, arbitrary, and empirical functions, including inflections. Abbreviated VDFG.