manipulate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• transitive verb To move, arrange, operate, or control by the hands or another body part or by mechanical means, especially in a skillful manner: synonym: handle.
• transitive verb To influence or manage shrewdly or deviously.
• transitive verb To tamper with or falsify for personal gain.
• transitive verb Medicine To handle and move in an examination or for therapeutic purposes.

from The Century Dictionary.

• 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.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To use the hands in dexterous operations; to do hand work
• transitive verb To treat, work, or operate with the hands, especially when knowledge and dexterity are required; to manage in hand work; to handle.
• transitive verb To control the action of, by management; also, to manage artfully or fraudulently.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To move, arrange or operate something using the hands
• verb transitive To influence, manage, direct, control or tamper with something
• verb transitive, medicine To handle and move a body part, either as an examination or for a therapeutic purpose

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb hold something in one's hands and move it
• verb influence or control shrewdly or deviously
• verb control (others or oneself) or influence skillfully, usually to one's advantage
• verb treat manually, as with massage, for therapeutic purposed
• verb tamper, with the purpose of deception
• verb manipulate in a fraudulent manner