To handle, or act on with the hands, as in artistic or mechanical operations; hence, in general, to subject to certain mechanical operations or to some method of handling, arranging, combining, etc.: as, the chemist exercises great care in manipulating his materials and apparatus.Figuratively, to operate upon by contrivance or influence; affect in a particular way by a definite course of treatment; manage; specifically, to manage insidiously; adapt or apply to one's own purpose or advantage; treat or use falsely or deceptively: as, to manipulate accounts or the facts of history (with the purpose of falsifying them).To use the hands, as in mechanical or artistic operations, scientific experiments, mesmerism, etc.: as, to manipulate neatly or successfully.